Common Weakness Enumeration

CWE-116

Allowed-with-Review

Improper Encoding or Escaping of Output

Abstraction: Class · Status: Draft

API response cwe.mitre.org

The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.

694 vulnerabilities reference this CWE, most recent first.

GHSA-R5VX-68X4-4JCF

Vulnerability from github – Published: 2025-04-11 18:31 – Updated: 2025-11-03 21:33
VLAI
Details

Improper Encoding or Escaping of Output vulnerability in The Wikimedia Foundation Mediawiki Core - Feed Utils allows WebView Injection.This issue affects Mediawiki Core - Feed Utils: from 1.39 through 1.43.

Severity
6.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L
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{
  "affected": [],
  "aliases": [
    "CVE-2025-32072"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-04-11T17:15:43Z",
    "severity": "MODERATE"
  },
  "details": "Improper Encoding or Escaping of Output vulnerability in The Wikimedia Foundation Mediawiki Core - Feed Utils allows WebView Injection.This issue affects Mediawiki Core - Feed Utils: from 1.39 through 1.43.",
  "id": "GHSA-r5vx-68x4-4jcf",
  "modified": "2025-11-03T21:33:30Z",
  "published": "2025-04-11T18:31:07Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-32072"
    },
    {
      "type": "WEB",
      "url": "https://gerrit.wikimedia.org/r/c/mediawiki/core/+/1120134"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/07/msg00012.html"
    },
    {
      "type": "WEB",
      "url": "https://phabricator.wikimedia.org/T386175"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

GHSA-R67M-MF7V-QP7J

Vulnerability from github – Published: 2023-11-06 18:30 – Updated: 2025-07-22 17:17
VLAI
Summary
Mattermost password hash disclosure vulnerability
Details

Mattermost fails to properly sanitize the user object when updating the username, resulting in the password hash being included in the response body. 

Severity
4.9 (Medium)
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server/v6"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.4.0-rc1"
            },
            {
              "fixed": "7.8.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost/server/v8"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.0.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost/server/v8"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.1.0"
            },
            {
              "fixed": "8.1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost/server/v8"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "9.0.0"
            },
            {
              "fixed": "9.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "9.0.0"
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost/server/v8"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.0.0-20230825233148-f787fd63368a"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server/v6"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.3.2-0.20230825233148-f787fd63368a"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server/v5"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.3.2-0.20230825233148-f787fd63368a"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.3.2-0.20230825233148-f787fd63368a"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-5968"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116",
      "CWE-200"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-11-08T14:58:02Z",
    "nvd_published_at": "2023-11-06T16:15:42Z",
    "severity": "MODERATE"
  },
  "details": "Mattermost fails to properly sanitize the user object when updating the username, resulting in the password hash being included in the response body.\u00a0",
  "id": "GHSA-r67m-mf7v-qp7j",
  "modified": "2025-07-22T17:17:20Z",
  "published": "2023-11-06T18:30:19Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-5968"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mattermost/mattermost/pull/24362"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mattermost/mattermost/pull/24566"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mattermost/mattermost/commit/698f4a97da564e2c1f2bf1fbd01755cefa3b7881"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/mattermost/mattermost"
    },
    {
      "type": "WEB",
      "url": "https://mattermost.com/security-updates"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Mattermost password hash disclosure vulnerability"
}

GHSA-R8X2-FHMF-6MXP

Vulnerability from github – Published: 2026-03-18 13:00 – Updated: 2026-04-27 15:22
VLAI
Summary
Heimdall: Path received via Envoy gRPC corrupted when containing query string
Details

Summary

When using heimdall in envoy gRPC decision API mode, wrong encoding of the query URL string allows rules with non-wildcard path expressions to be bypassed.

The HTTP based decision API is NOT affected, and proxy mode is NOT affected either.

Note: The issue can only lead to unintended access if heimdall is configured with an "allow all" default rule. Since v0.16.0, heimdall enforces secure defaults and refuses to start with such a configuration unless this enforcement is explicitly disabled, e.g. via --insecure-skip-secure-default-rule-enforcement or the broader --insecure flag.

Details

Envoy splits the requested URL into parts, and sends the parts individually to heimdall. Although query and path are present in the API, the query field is documented to be always empty and the URL query is included in the path field [1].

The implementation uses go's url library to reconstruct the url which automatically encodes special characters in the path.

https://github.com/dadrus/heimdall/blob/1faba9e4160bd7ab3240cf6aa418e21bfef3401a/internal/handler/envoyextauth/grpcv3/request_context.go#L109-L115

As a consequence, a parameter like /mypath?foo=bar to Path is escaped into /mypath%3Ffoo=bar. Subsequently, a rule matching /mypath no longer matches and is bypassed.

PoC

Using the example docker compose setup, the demo:public rule is bypassed when adding a query parameter.

docker compose -f docker-compose-envoy-grpc.yaml -f docker-compose.yaml up

curl http://127.0.0.1:9090/public
Hostname: 80201fead1c7
IP: 127.0.0.1
IP: ::1
IP: 172.23.0.3
RemoteAddr: 172.23.0.5:37056
GET /public HTTP/1.1
Host: 127.0.0.1:9090
User-Agent: curl/8.19.0
Accept: */*
X-Envoy-Expected-Rq-Timeout-Ms: 15000
X-Forwarded-Proto: http
X-Request-Id: 0a1f0f06-75ef-4f14-92af-16162ea1d9e5

curl -v http://127.0.0.1:9090/public?bypass
*   Trying 127.0.0.1:9090...
* Established connection to 127.0.0.1 (127.0.0.1 port 9090) from 127.0.0.1 port 47876 
* using HTTP/1.x
> GET /public?hallo HTTP/1.1
> Host: 127.0.0.1:9090
> User-Agent: curl/8.19.0
> Accept: */*
> 
* Request completely sent off
< HTTP/1.1 401 Unauthorized
< date: Sat, 14 Mar 2026 16:34:17 GMT
< server: envoy
< content-length: 0
< 
* Connection #0 to host 127.0.0.1:9090 left intact

When using the HTTP decision API variant, the second request is matched by the rule as well:

docker compose -f docker-compose-envoy-http.yaml -f docker-compose.yaml up

curl http://127.0.0.1:9090/public?bypass
Hostname: 80201fead1c7
IP: 127.0.0.1
IP: ::1
IP: 172.23.0.4
RemoteAddr: 172.23.0.2:38044
GET /public?hallo HTTP/1.1
Host: 127.0.0.1:9090
User-Agent: curl/8.19.0
Accept: */*
X-Envoy-Expected-Rq-Timeout-Ms: 15000
X-Forwarded-Proto: http
X-Request-Id: 5c961bc6-ad03-4a44-982b-abe04566fdd2

Impact

Everyone using heimdall with the envoy gRPC API may be affected. Users who configured a deny list in heimdall (with an allow-all default rule) are affected, as attackers can potentially circumvent a specific block rule by adding query parameters.

[1] https://github.com/envoyproxy/envoy/blob/105b4acd422d67fcff908ec38d91c7676d079939/api/envoy/service/auth/v3/attribute_context.proto#L146-L147

Severity
8.2 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.17.10"
      },
      "package": {
        "ecosystem": "Go",
        "name": "github.com/dadrus/heimdall"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.7.0-alpha"
            },
            {
              "fixed": "0.17.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-32811"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116",
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-18T13:00:56Z",
    "nvd_published_at": "2026-03-20T02:16:34Z",
    "severity": "HIGH"
  },
  "details": "### Summary\nWhen using heimdall in envoy gRPC decision API mode, wrong encoding of the query URL string allows rules with non-wildcard path expressions to be bypassed.\n\nThe HTTP based decision API is NOT affected, and proxy mode is NOT affected either.\n\n**Note:** The issue can only lead to unintended access if heimdall is configured with an \"allow all\" default rule. Since v0.16.0, heimdall enforces secure defaults and refuses to start with such a configuration unless this enforcement is explicitly disabled, e.g. via `--insecure-skip-secure-default-rule-enforcement` or the broader `--insecure` flag.\n\n### Details\nEnvoy splits the requested URL into parts, and sends the parts individually to heimdall. Although `query` and `path` are present in the API, the `query` field is documented to be always empty and the URL query is included in the `path` field [1].\n\nThe implementation uses go\u0027s url library to reconstruct the url which automatically encodes special characters in the path. \n\n https://github.com/dadrus/heimdall/blob/1faba9e4160bd7ab3240cf6aa418e21bfef3401a/internal/handler/envoyextauth/grpcv3/request_context.go#L109-L115\n\nAs a consequence, a parameter like `/mypath?foo=bar` to `Path`  is escaped into  `/mypath%3Ffoo=bar`. Subsequently, a rule matching `/mypath` no longer matches and is bypassed.\n\n\n### PoC\n\nUsing the example docker compose setup, the `demo:public` rule is bypassed when adding a query parameter.\n\n\u003e docker compose -f docker-compose-envoy-grpc.yaml -f docker-compose.yaml up\n\n```\ncurl http://127.0.0.1:9090/public\nHostname: 80201fead1c7\nIP: 127.0.0.1\nIP: ::1\nIP: 172.23.0.3\nRemoteAddr: 172.23.0.5:37056\nGET /public HTTP/1.1\nHost: 127.0.0.1:9090\nUser-Agent: curl/8.19.0\nAccept: */*\nX-Envoy-Expected-Rq-Timeout-Ms: 15000\nX-Forwarded-Proto: http\nX-Request-Id: 0a1f0f06-75ef-4f14-92af-16162ea1d9e5\n\ncurl -v http://127.0.0.1:9090/public?bypass\n*   Trying 127.0.0.1:9090...\n* Established connection to 127.0.0.1 (127.0.0.1 port 9090) from 127.0.0.1 port 47876 \n* using HTTP/1.x\n\u003e GET /public?hallo HTTP/1.1\n\u003e Host: 127.0.0.1:9090\n\u003e User-Agent: curl/8.19.0\n\u003e Accept: */*\n\u003e \n* Request completely sent off\n\u003c HTTP/1.1 401 Unauthorized\n\u003c date: Sat, 14 Mar 2026 16:34:17 GMT\n\u003c server: envoy\n\u003c content-length: 0\n\u003c \n* Connection #0 to host 127.0.0.1:9090 left intact\n```\n\nWhen using the HTTP decision API variant, the second request is matched by the rule as well:\n\n\u003e docker compose -f docker-compose-envoy-http.yaml -f docker-compose.yaml up\n\n```\ncurl http://127.0.0.1:9090/public?bypass\nHostname: 80201fead1c7\nIP: 127.0.0.1\nIP: ::1\nIP: 172.23.0.4\nRemoteAddr: 172.23.0.2:38044\nGET /public?hallo HTTP/1.1\nHost: 127.0.0.1:9090\nUser-Agent: curl/8.19.0\nAccept: */*\nX-Envoy-Expected-Rq-Timeout-Ms: 15000\nX-Forwarded-Proto: http\nX-Request-Id: 5c961bc6-ad03-4a44-982b-abe04566fdd2\n```\n\n### Impact\n\nEveryone using heimdall with the envoy gRPC API may be affected. Users who configured a deny list in heimdall (with an allow-all default rule) are affected, as attackers can potentially circumvent a specific block rule by adding query parameters.\n\n[1] https://github.com/envoyproxy/envoy/blob/105b4acd422d67fcff908ec38d91c7676d079939/api/envoy/service/auth/v3/attribute_context.proto#L146-L147",
  "id": "GHSA-r8x2-fhmf-6mxp",
  "modified": "2026-04-27T15:22:43Z",
  "published": "2026-03-18T13:00:56Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/dadrus/heimdall/security/advisories/GHSA-r8x2-fhmf-6mxp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-32811"
    },
    {
      "type": "WEB",
      "url": "https://github.com/dadrus/heimdall/pull/3106"
    },
    {
      "type": "WEB",
      "url": "https://github.com/dadrus/heimdall/commit/50321b3007db1ccafdc6b1cfd6bdc3689c19a502"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/dadrus/heimdall"
    },
    {
      "type": "WEB",
      "url": "https://github.com/envoyproxy/envoy/blob/105b4acd422d67fcff908ec38d91c7676d079939/api/envoy/service/auth/v3/attribute_context.proto#L146-L147"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Heimdall: Path received via Envoy gRPC corrupted when containing query string"
}

GHSA-RC4R-C73W-WXQX

Vulnerability from github – Published: 2023-11-24 00:30 – Updated: 2023-11-24 00:30
VLAI
Details

IBM QRadar WinCollect Agent 10.0 through 10.1.7 could allow a local user to perform unauthorized actions due to improper encoding. IBM X-Force ID: 248160.

Severity
3.3 (Low)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2023-26279"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2023-11-24T00:15:10Z",
    "severity": "LOW"
  },
  "details": "\nIBM QRadar WinCollect Agent 10.0 through 10.1.7 could allow a local user to perform unauthorized actions due to improper encoding.  IBM X-Force ID:  248160.\n\n",
  "id": "GHSA-rc4r-c73w-wxqx",
  "modified": "2023-11-24T00:30:34Z",
  "published": "2023-11-24T00:30:34Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-26279"
    },
    {
      "type": "WEB",
      "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/213551"
    },
    {
      "type": "WEB",
      "url": "https://www.ibm.com/support/pages/node/7081403"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-RCXC-FHH3-QJQ9

Vulnerability from github – Published: 2023-11-14 21:30 – Updated: 2023-11-14 21:30
VLAI
Details

Docker Machine through 0.16.2 allows an attacker, who has control of a worker node, to provide crafted version data, which might potentially trick an administrator into performing an unsafe action (via escape sequence injection), or might have a data size that causes a denial of service to a bastion node. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.

Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2023-40453"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2023-11-07T04:20:15Z",
    "severity": "MODERATE"
  },
  "details": "Docker Machine through 0.16.2 allows an attacker, who has control of a worker node, to provide crafted version data, which might potentially trick an administrator into performing an unsafe action (via escape sequence injection), or might have a data size that causes a denial of service to a bastion node. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.",
  "id": "GHSA-rcxc-fhh3-qjq9",
  "modified": "2023-11-14T21:30:51Z",
  "published": "2023-11-14T21:30:51Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-40453"
    },
    {
      "type": "WEB",
      "url": "https://hackerone.com/reports/1916285"
    },
    {
      "type": "WEB",
      "url": "https://github.com/docker/machine/releases"
    },
    {
      "type": "WEB",
      "url": "https://vin01.github.io/piptagole/docker/security/gitlab/docker-machine/2023/07/07/docker-machine-attack-surface.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-RF6G-CF9F-G4V7

Vulnerability from github – Published: 2025-10-14 15:31 – Updated: 2025-11-03 18:31
VLAI
Details

A malicious page could have used the type attribute of an OBJECT tag to override the default browser behavior when encountering a web resource served without a content-type. This could have contributed to an XSS on a site that unsafely serves files without a content-type header. This vulnerability affects Firefox < 144, Firefox ESR < 140.4, Thunderbird < 144, and Thunderbird < 140.4.

Severity
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2025-11712"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-10-14T13:15:37Z",
    "severity": "MODERATE"
  },
  "details": "A malicious page could have used the type attribute of an OBJECT tag to override the default browser behavior when encountering a web resource served without a content-type. This could have contributed to an XSS on a site that unsafely serves files without a content-type header. This vulnerability affects Firefox \u003c 144, Firefox ESR \u003c 140.4, Thunderbird \u003c 144, and Thunderbird \u003c 140.4.",
  "id": "GHSA-rf6g-cf9f-g4v7",
  "modified": "2025-11-03T18:31:46Z",
  "published": "2025-10-14T15:31:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-11712"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1979536"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00015.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00031.html"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2025-81"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2025-83"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2025-84"
    },
    {
      "type": "WEB",
      "url": "https://www.mozilla.org/security/advisories/mfsa2025-85"
    }
  ],
  "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-RHGR-952R-6P8Q

Vulnerability from github – Published: 2022-05-24 00:01 – Updated: 2022-09-08 14:20
VLAI
Summary
Command injection in Apache Maven maven-shared-utils
Details

In Apache Maven maven-shared-utils prior to version 3.3.3, the Commandline class can emit double-quoted strings without proper escaping, allowing shell injection attacks.

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.apache.maven.shared:maven-shared-utils"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.3.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2022-29599"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116",
      "CWE-77"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2022-05-25T22:39:47Z",
    "nvd_published_at": "2022-05-23T11:16:00Z",
    "severity": "CRITICAL"
  },
  "details": "In Apache Maven maven-shared-utils prior to version 3.3.3, the Commandline class can emit double-quoted strings without proper escaping, allowing shell injection attacks.",
  "id": "GHSA-rhgr-952r-6p8q",
  "modified": "2022-09-08T14:20:02Z",
  "published": "2022-05-24T00:01:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-29599"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apache/maven-shared-utils/pull/40"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/apache/maven-shared-utils"
    },
    {
      "type": "WEB",
      "url": "https://issues.apache.org/jira/browse/MSHARED-297"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2022/08/msg00018.html"
    },
    {
      "type": "WEB",
      "url": "https://www.debian.org/security/2022/dsa-5242"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2022/05/23/3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Command injection in Apache Maven maven-shared-utils"
}

GHSA-RM3P-6J6M-68Q8

Vulnerability from github – Published: 2022-11-21 12:30 – Updated: 2022-11-23 18:30
VLAI
Details

The Five Star Restaurant Reservations WordPress plugin before 2.4.12 does not have authorisation when changing whether a payment was successful or failed, allowing unauthenticated users to change the payment status of arbitrary bookings. Furthermore, due to the lack of sanitisation and escaping, attackers could perform Cross-Site Scripting attacks against a logged in admin viewing the failed payments

Severity
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2022-0421"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116",
      "CWE-79",
      "CWE-862"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2022-11-21T11:15:00Z",
    "severity": "MODERATE"
  },
  "details": "The Five Star Restaurant Reservations WordPress plugin before 2.4.12 does not have authorisation when changing whether a payment was successful or failed, allowing unauthenticated users to change the payment status of arbitrary bookings. Furthermore, due to the lack of sanitisation and escaping, attackers could perform Cross-Site Scripting attacks against a logged in admin viewing the failed payments",
  "id": "GHSA-rm3p-6j6m-68q8",
  "modified": "2022-11-23T18:30:29Z",
  "published": "2022-11-21T12:30:17Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-0421"
    },
    {
      "type": "WEB",
      "url": "https://wpscan.com/vulnerability/145e8d3c-cd6f-4827-86e5-ea2d395a80b9"
    }
  ],
  "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-RQ2W-37H9-VG94

Vulnerability from github – Published: 2023-01-03 21:30 – Updated: 2024-04-23 21:44
VLAI
Summary
Apache Tomcat improperly escapes input from JsonErrorReportValve
Details

The JsonErrorReportValve in Apache Tomcat 8.5.83, 9.0.40 to 9.0.68 and 10.1.0-M1 to 10.1.1 does not escape the type, message or description values. In some circumstances these are constructed from user provided data and it was therefore possible for users to supply values that invalidated or manipulated the JSON output.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.apache.tomcat.embed:tomcat-embed-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.5.83"
            },
            {
              "fixed": "8.5.84"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "8.5.83"
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 9.0.68"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.apache.tomcat.embed:tomcat-embed-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "9.0.40"
            },
            {
              "fixed": "9.0.69"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 10.1.1"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.apache.tomcat.embed:tomcat-embed-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "10.1.0"
            },
            {
              "fixed": "10.1.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 10.1.1"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.apache.tomcat:tomcat-catalina"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "10.1.0"
            },
            {
              "fixed": "10.1.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.apache.tomcat:tomcat-util"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.5.83"
            },
            {
              "fixed": "8.5.84"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "8.5.83"
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.apache.tomcat:tomcat-util"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "9.0.40"
            },
            {
              "fixed": "9.0.69"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2022-45143"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116",
      "CWE-74"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-01-05T12:02:50Z",
    "nvd_published_at": "2023-01-03T19:15:00Z",
    "severity": "HIGH"
  },
  "details": "The `JsonErrorReportValve` in Apache Tomcat 8.5.83, 9.0.40 to 9.0.68 and 10.1.0-M1 to 10.1.1 does not escape the `type`, `message` or `description` values. In some circumstances these are constructed from user provided data and it was therefore possible for users to supply values that invalidated or manipulated the JSON output.",
  "id": "GHSA-rq2w-37h9-vg94",
  "modified": "2024-04-23T21:44:48Z",
  "published": "2023-01-03T21:30:21Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-45143"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apache/tomcat/commit/0cab3a56bd89f70e7481bb0d68395dc7e130dbbf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apache/tomcat/commit/6a0ac6a438cbbb66b6e9c5223842f53bf0cb50aa"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apache/tomcat/commit/b336f4e58893ea35114f1e4a415657f723b1298e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/apache/tomcat"
    },
    {
      "type": "WEB",
      "url": "https://lists.apache.org/thread/yqkd183xrw3wqvnpcg3osbcryq85fkzj"
    },
    {
      "type": "WEB",
      "url": "https://security.gentoo.org/glsa/202305-37"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Apache Tomcat improperly escapes input from JsonErrorReportValve"
}

GHSA-RQV2-M695-F8J4

Vulnerability from github – Published: 2026-05-08 17:18 – Updated: 2026-05-15 23:46
VLAI
Summary
MCP Registry vulnerable to stored XSS in catalogue UI via attribute-quote breakout in publisher-controlled `websiteUrl`
Details

Summary

The public catalogue UI served at GET / (file internal/api/handlers/v0/ui_index.html) is vulnerable to stored cross-site scripting via the server.websiteUrl field of any published server.json. Server-side validation in internal/validators/validators.go (validateWebsiteURL) only checks that the URL parses, is absolute, and uses the https scheme; it does not reject quote characters. Client-side, the value is interpolated into a double-quoted href attribute via innerHTML, using a homegrown escapeHtml helper that performs the standard textContent → innerHTML round-trip. Per the HTML serialisation algorithm, that round-trip encodes only &, <, > and U+00A0 inside text nodes — it does not encode " or '. A literal " in websiteUrl therefore breaks out of the href attribute, allowing arbitrary on* event handlers to be appended to the same <a> element. The Content-Security-Policy on / is script-src 'self' 'unsafe-inline' https://cdn.tailwindcss.com, so the injected event handlers execute.

Any user able to obtain a publish token (e.g. via POST /v0/auth/github-at with their own GitHub account, or POST /v0/auth/none on a deployment that has anonymous auth enabled) can plant a poisoned record visible to every visitor of the registry homepage.

Affected component

  • Validator: internal/validators/validators.go — validateWebsiteURL (lines 153–199)
  • Sink: internal/api/handlers/v0/ui_index.html — toggleDetails(card, item) at line 432, the href attribute built around escapeHtml(server.websiteUrl)
  • Helper: escapeHtml defined at internal/api/handlers/v0/ui_index.html lines 494–498

Proof of concept

  1. Obtain a Registry JWT for any namespace you control (a GitHub OAuth exchange against a throwaway account suffices):

bash TOKEN=$(curl -sS -X POST https://registry.modelcontextprotocol.io/v0/auth/github-at \ -H 'Content-Type: application/json' \ -d '{"github_token":"<gh-pat>"}' | jq -r .registry_token)

  1. Publish a server with a poisoned websiteUrl. The literal " is preserved end-to-end:

bash curl -sS -X POST https://registry.modelcontextprotocol.io/v0/publish \ -H "Authorization: Bearer $TOKEN" \ -H 'Content-Type: application/json' \ --data-binary @- <<'EOF' { "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json", "name": "io.github.<your-account>/xss-poc", "version": "0.0.1", "description": "hover the website link", "websiteUrl": "https://example.com/\"onmouseover=alert(document.domain)//" } EOF

  1. Visit https://registry.modelcontextprotocol.io/, search for xss-poc, click the card to expand it, then hover the Website link in the details panel. The injected onmouseover fires and alert(document.domain) runs on the registry.modelcontextprotocol.io origin.

Why server-side validation does not catch this

Go's net/url.Parse accepts literal " in the path component:

input="https://example.com/\"onmouseover=alert(1)//"  IsAbs=true  Scheme="https"  Path="/\"onmouseover=alert(1)//"

Neither the Huma format:"uri" annotation nor validateWebsiteURL's scheme/IsAbs triplet rejects this string. The architecture's existing protection — repository.url is regex-locked to ^https?://(www\.)?github\.com/[\w.-]+/[\w.-]+/?$ and therefore cannot contain quotes — does not extend to websiteUrl, which has no allowlist.

Why client-side escapeHtml does not catch this

function escapeHtml(text) {
    const div = document.createElement('div');
    div.textContent = text;
    return div.innerHTML;
}

Per the HTML5 spec (§13.3 Serialising HTML fragments), the only characters encoded inside the text content of an element are &, <, >, and U+00A0. " and ' are not encoded because in a text-content context they are not special. The helper is therefore safe in element-text contexts (where it is correctly used for name, version, description, etc.) but unsafe inside an attribute value, which is precisely where it is invoked for href on lines 432 and 426.

Impact

  • Stored XSS on the official MCP Registry homepage. The malicious entry sits in the public catalogue alongside legitimate ones; any user expanding the entry triggers the payload.
  • Because the page is served on the official registry.modelcontextprotocol.io origin, the injected script can:
  • Read and overwrite localStorage (baseUrl, customUrl), pinning the user's subsequent reads to an attacker-controlled "Custom" base URL.
  • Issue any same-origin or cross-origin XHR (connect-src * is granted).
  • Phish for Registry JWTs by injecting fake auth flows on the trusted origin.
  • The CSP script-src 'self' 'unsafe-inline' https://cdn.tailwindcss.com does not block this because 'unsafe-inline' permits inline event-handler attributes.

Suggested remediation (any one suffices)

  1. Replace the homegrown escapeHtml with an attribute-safe encoder that also escapes ", ', backtick, and = — the OWASP HTML attribute-encoding rule.
  2. Avoid building the href via string templates. Use setAttribute('href', value) instead — setAttribute is not subject to HTML tokenisation, so no breakout is possible.
  3. Tighten validateWebsiteURL to reject any URL whose raw bytes contain ", ', <, >, , \t, or \n, or — conservatively — store the canonical re-serialised form (parsedURL.String() percent-encodes such characters in the path).
  4. Drop 'unsafe-inline' from script-src after auditing the inline scripts on the page.

Approach (3) is the smallest server-side change and immediately neutralises the exploit for any new publishes; approaches (1) or (2) close the class of bug at the sink so future fields with similar patterns are safe by default.

Severity
5.4 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
5.1 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:L
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/modelcontextprotocol/registry"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.7.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44429"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116",
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-08T17:18:32Z",
    "nvd_published_at": "2026-05-14T21:16:46Z",
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nThe public catalogue UI served at `GET /` (file `internal/api/handlers/v0/ui_index.html`) is vulnerable to stored cross-site scripting via the `server.websiteUrl` field of any published `server.json`. Server-side validation in `internal/validators/validators.go` (`validateWebsiteURL`) only checks that the URL parses, is absolute, and uses the `https` scheme; it does not reject quote characters. Client-side, the value is interpolated into a double-quoted `href` attribute via `innerHTML`, using a homegrown `escapeHtml` helper that performs the standard `textContent` \u2192 `innerHTML` round-trip. Per the HTML serialisation algorithm, that round-trip encodes only `\u0026`, `\u003c`, `\u003e` and U+00A0 inside text nodes \u2014 it does **not** encode `\"` or `\u0027`. A literal `\"` in `websiteUrl` therefore breaks out of the `href` attribute, allowing arbitrary `on*` event handlers to be appended to the same `\u003ca\u003e` element. The Content-Security-Policy on `/` is `script-src \u0027self\u0027 \u0027unsafe-inline\u0027 https://cdn.tailwindcss.com`, so the injected event handlers execute.\n\nAny user able to obtain a publish token (e.g. via `POST /v0/auth/github-at` with their own GitHub account, or `POST /v0/auth/none` on a deployment that has anonymous auth enabled) can plant a poisoned record visible to every visitor of the registry homepage.\n\n## Affected component\n\n- Validator: `internal/validators/validators.go` \u2014 `validateWebsiteURL` (lines 153\u2013199)\n- Sink: `internal/api/handlers/v0/ui_index.html` \u2014 `toggleDetails(card, item)` at line 432, the `href` attribute built around `escapeHtml(server.websiteUrl)`\n- Helper: `escapeHtml` defined at `internal/api/handlers/v0/ui_index.html` lines 494\u2013498\n\n## Proof of concept\n\n1. Obtain a Registry JWT for any namespace you control (a GitHub OAuth exchange against a throwaway account suffices):\n\n   ```bash\n   TOKEN=$(curl -sS -X POST https://registry.modelcontextprotocol.io/v0/auth/github-at \\\n        -H \u0027Content-Type: application/json\u0027 \\\n        -d \u0027{\"github_token\":\"\u003cgh-pat\u003e\"}\u0027 | jq -r .registry_token)\n   ```\n\n2. Publish a server with a poisoned `websiteUrl`. The literal `\"` is preserved end-to-end:\n\n   ```bash\n   curl -sS -X POST https://registry.modelcontextprotocol.io/v0/publish \\\n     -H \"Authorization: Bearer $TOKEN\" \\\n     -H \u0027Content-Type: application/json\u0027 \\\n     --data-binary @- \u003c\u003c\u0027EOF\u0027\n   {\n     \"$schema\": \"https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json\",\n     \"name\":  \"io.github.\u003cyour-account\u003e/xss-poc\",\n     \"version\": \"0.0.1\",\n     \"description\": \"hover the website link\",\n     \"websiteUrl\": \"https://example.com/\\\"onmouseover=alert(document.domain)//\"\n   }\n   EOF\n   ```\n\n3. Visit `https://registry.modelcontextprotocol.io/`, search for `xss-poc`, click the card to expand it, then hover the **Website** link in the details panel. The injected `onmouseover` fires and `alert(document.domain)` runs on the `registry.modelcontextprotocol.io` origin.\n\n## Why server-side validation does not catch this\n\nGo\u0027s `net/url.Parse` accepts literal `\"` in the path component:\n\n```\ninput=\"https://example.com/\\\"onmouseover=alert(1)//\"  IsAbs=true  Scheme=\"https\"  Path=\"/\\\"onmouseover=alert(1)//\"\n```\n\nNeither the Huma `format:\"uri\"` annotation nor `validateWebsiteURL`\u0027s scheme/`IsAbs` triplet rejects this string. The architecture\u0027s existing protection \u2014 `repository.url` is regex-locked to `^https?://(www\\.)?github\\.com/[\\w.-]+/[\\w.-]+/?$` and therefore cannot contain quotes \u2014 does not extend to `websiteUrl`, which has no allowlist.\n\n## Why client-side `escapeHtml` does not catch this\n\n```js\nfunction escapeHtml(text) {\n    const div = document.createElement(\u0027div\u0027);\n    div.textContent = text;\n    return div.innerHTML;\n}\n```\n\nPer the HTML5 spec (\u00a713.3 Serialising HTML fragments), the only characters encoded inside the text content of an element are `\u0026`, `\u003c`, `\u003e`, and U+00A0. `\"` and `\u0027` are **not** encoded because in a text-content context they are not special. The helper is therefore safe in element-text contexts (where it is correctly used for `name`, `version`, `description`, etc.) but unsafe inside an attribute value, which is precisely where it is invoked for `href` on lines 432 and 426.\n\n## Impact\n\n- Stored XSS on the official MCP Registry homepage. The malicious entry sits in the public catalogue alongside legitimate ones; any user expanding the entry triggers the payload.\n- Because the page is served on the official `registry.modelcontextprotocol.io` origin, the injected script can:\n  - Read and overwrite `localStorage` (`baseUrl`, `customUrl`), pinning the user\u0027s subsequent reads to an attacker-controlled \"Custom\" base URL.\n  - Issue any same-origin or cross-origin XHR (`connect-src *` is granted).\n  - Phish for Registry JWTs by injecting fake auth flows on the trusted origin.\n- The CSP `script-src \u0027self\u0027 \u0027unsafe-inline\u0027 https://cdn.tailwindcss.com` does not block this because `\u0027unsafe-inline\u0027` permits inline event-handler attributes.\n\n## Suggested remediation (any one suffices)\n\n1. Replace the homegrown `escapeHtml` with an attribute-safe encoder that also escapes `\"`, `\u0027`, backtick, and `=` \u2014 the OWASP HTML attribute-encoding rule.\n2. Avoid building the `href` via string templates. Use `setAttribute(\u0027href\u0027, value)` instead \u2014 `setAttribute` is not subject to HTML tokenisation, so no breakout is possible.\n3. Tighten `validateWebsiteURL` to reject any URL whose raw bytes contain `\"`, `\u0027`, `\u003c`, `\u003e`, ` `, `\\t`, or `\\n`, or \u2014 conservatively \u2014 store the canonical re-serialised form (`parsedURL.String()` percent-encodes such characters in the path).\n4. Drop `\u0027unsafe-inline\u0027` from `script-src` after auditing the inline scripts on the page.\n\nApproach (3) is the smallest server-side change and immediately neutralises the exploit for any new publishes; approaches (1) or (2) close the class of bug at the sink so future fields with similar patterns are safe by default.",
  "id": "GHSA-rqv2-m695-f8j4",
  "modified": "2026-05-15T23:46:13Z",
  "published": "2026-05-08T17:18:32Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-rqv2-m695-f8j4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44429"
    },
    {
      "type": "WEB",
      "url": "https://github.com/modelcontextprotocol/registry/pull/1249"
    },
    {
      "type": "WEB",
      "url": "https://github.com/modelcontextprotocol/registry/commit/78b7bbde07948049b916d76b4769faee461ff930"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/modelcontextprotocol/registry"
    },
    {
      "type": "WEB",
      "url": "https://github.com/modelcontextprotocol/registry/releases/tag/v1.7.7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:L",
      "type": "CVSS_V4"
    }
  ],
  "summary": "MCP Registry vulnerable to stored XSS in catalogue UI via attribute-quote breakout in publisher-controlled `websiteUrl`"
}
Mitigation MIT-4.3
Architecture and Design

Strategy: Libraries or Frameworks

  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
  • For example, consider using the ESAPI Encoding control [REF-45] or a similar tool, library, or framework. These will help the programmer encode outputs in a manner less prone to error.
  • Alternately, use built-in functions, but consider using wrappers in case those functions are discovered to have a vulnerability.
Mitigation MIT-27
Architecture and Design

Strategy: Parameterization

  • If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
  • For example, stored procedures can enforce database query structure and reduce the likelihood of SQL injection.
Mitigation
Architecture and Design Implementation

Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages. Study all expected communication protocols and data representations to determine the required encoding strategies.

Mitigation
Architecture and Design

In some cases, input validation may be an important strategy when output encoding is not a complete solution. For example, you may be providing the same output that will be processed by multiple consumers that use different encodings or representations. In other cases, you may be required to allow user-supplied input to contain control information, such as limited HTML tags that support formatting in a wiki or bulletin board. When this type of requirement must be met, use an extremely strict allowlist to limit which control sequences can be used. Verify that the resulting syntactic structure is what you expect. Use your normal encoding methods for the remainder of the input.

Mitigation
Architecture and Design

Use input validation as a defense-in-depth measure to reduce the likelihood of output encoding errors (see CWE-20).

Mitigation
Requirements

Fully specify which encodings are required by components that will be communicating with each other.

Mitigation
Implementation

When exchanging data between components, ensure that both components are using the same character encoding. Ensure that the proper encoding is applied at each interface. Explicitly set the encoding you are using whenever the protocol allows you to do so.

CAPEC-104: Cross Zone Scripting

An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security.

CAPEC-73: User-Controlled Filename

An attack of this type involves an adversary inserting malicious characters (such as a XSS redirection) into a filename, directly or indirectly that is then used by the target software to generate HTML text or other potentially executable content. Many websites rely on user-generated content and dynamically build resources like files, filenames, and URL links directly from user supplied data. In this attack pattern, the attacker uploads code that can execute in the client browser and/or redirect the client browser to a site that the attacker owns. All XSS attack payload variants can be used to pass and exploit these vulnerabilities.

CAPEC-81: Web Server Logs Tampering

Web Logs Tampering attacks involve an attacker injecting, deleting or otherwise tampering with the contents of web logs typically for the purposes of masking other malicious behavior. Additionally, writing malicious data to log files may target jobs, filters, reports, and other agents that process the logs in an asynchronous attack pattern. This pattern of attack is similar to "Log Injection-Tampering-Forging" except that in this case, the attack is targeting the logs of the web server and not the application.

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.

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