CWE-601
AllowedURL Redirection to Untrusted Site ('Open Redirect')
Abstraction: Base · Status: Draft
The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.
2303 vulnerabilities reference this CWE, most recent first.
GHSA-3CQ7-3XMJ-M7R2
Vulnerability from github – Published: 2022-01-18 00:01 – Updated: 2022-05-10 00:00The AnyComment WordPress plugin through 0.2.17 has an API endpoint which passes user input via the redirect parameter to the wp_redirect() function without being validated first, leading to an Open Redirect issue, which according to the vendor, is a feature.
{
"affected": [],
"aliases": [
"CVE-2021-24838"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-01-17T13:15:00Z",
"severity": "MODERATE"
},
"details": "The AnyComment WordPress plugin through 0.2.17 has an API endpoint which passes user input via the redirect parameter to the wp_redirect() function without being validated first, leading to an Open Redirect issue, which according to the vendor, is a feature.",
"id": "GHSA-3cq7-3xmj-m7r2",
"modified": "2022-05-10T00:00:49Z",
"published": "2022-01-18T00:01:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-24838"
},
{
"type": "WEB",
"url": "https://wpscan.com/vulnerability/562e81ad-7422-4437-a5b4-fcab9379db82"
}
],
"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-3CVX-WRCF-56R2
Vulnerability from github – Published: 2022-05-24 19:08 – Updated: 2022-05-24 19:08The specific function of the Orca HCM digital learning platform does not filter input parameters properly, which causing the URL can be redirected to any website. Remote attackers can use the vulnerability to execute phishing attacks.
{
"affected": [],
"aliases": [
"CVE-2021-35966"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-07-19T12:15:00Z",
"severity": "MODERATE"
},
"details": "The specific function of the Orca HCM digital learning platform does not filter input parameters properly, which causing the URL can be redirected to any website. Remote attackers can use the vulnerability to execute phishing attacks.",
"id": "GHSA-3cvx-wrcf-56r2",
"modified": "2022-05-24T19:08:23Z",
"published": "2022-05-24T19:08:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-35966"
},
{
"type": "WEB",
"url": "https://www.chtsecurity.com/news/ba7b3ae7-14f3-4970-b3f6-4d97d8c7ea25"
},
{
"type": "WEB",
"url": "https://www.twcert.org.tw/tw/cp-132-4926-dc06b-1.html"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-3CWX-Q62P-7M5H
Vulnerability from github – Published: 2022-05-13 01:31 – Updated: 2022-05-13 01:31Missing custom error page vulnerability in Synology Web Station before 2.1.3-0139 allows remote attackers to conduct phishing attacks via a crafted URL.
{
"affected": [],
"aliases": [
"CVE-2018-8913"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2019-04-01T15:29:00Z",
"severity": "MODERATE"
},
"details": "Missing custom error page vulnerability in Synology Web Station before 2.1.3-0139 allows remote attackers to conduct phishing attacks via a crafted URL.",
"id": "GHSA-3cwx-q62p-7m5h",
"modified": "2022-05-13T01:31:43Z",
"published": "2022-05-13T01:31:43Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-8913"
},
{
"type": "WEB",
"url": "https://www.synology.com/security/advisory/Synology_SA_18_29"
}
],
"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-3F58-74QW-PH75
Vulnerability from github – Published: 2022-05-17 03:59 – Updated: 2025-04-14 20:00The Flvplayer component in TYPO3 6.2.x before 6.2.16 allows remote attackers to embed Flash videos from external domains via unspecified vectors, aka "Cross-Site Flashing."
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "typo3/cms"
},
"ranges": [
{
"events": [
{
"introduced": "6.2.0"
},
{
"fixed": "6.2.16"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2015-8760"
],
"database_specific": {
"cwe_ids": [
"CWE-20",
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2025-04-14T20:00:11Z",
"nvd_published_at": "2016-01-08T19:59:00Z",
"severity": "MODERATE"
},
"details": "The Flvplayer component in TYPO3 6.2.x before 6.2.16 allows remote attackers to embed Flash videos from external domains via unspecified vectors, aka \"Cross-Site Flashing.\"",
"id": "GHSA-3f58-74qw-ph75",
"modified": "2025-04-14T20:00:11Z",
"published": "2022-05-17T03:59:51Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2015-8760"
},
{
"type": "WEB",
"url": "https://github.com/TYPO3/typo3/commit/29ae05c04cb48d4031d323f17d8f2b68b27af353"
},
{
"type": "PACKAGE",
"url": "https://github.com/TYPO3/typo3"
},
{
"type": "WEB",
"url": "https://typo3.org/security/advisory/typo3-core-sa-2015-014"
},
{
"type": "WEB",
"url": "https://web.archive.org/web/20160621232021/http://www.securityfocus.com/bid/79210"
},
{
"type": "WEB",
"url": "https://web.archive.org/web/20161012163613/http://www.securitytracker.com/id/1034485"
}
],
"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"
}
],
"summary": "TYPO3 allows remote attackers to embed Flash videos from external domain"
}
GHSA-3F6C-7FW2-PPM4
Vulnerability from github – Published: 2025-10-07 22:14 – Updated: 2025-10-27 20:00Summary
A Server-Side Request Forgery (SSRF) vulnerability exists in the MediaConnector class within the vLLM project's multimodal feature set. The load_from_url and load_from_url_async methods fetch and process media from user-provided URLs without adequate restrictions on the target hosts. This allows an attacker to coerce the vLLM server into making arbitrary requests to internal network resources.
This vulnerability is particularly critical in containerized environments like llm-d, where a compromised vLLM pod could be used to scan the internal network, interact with other pods, and potentially cause denial of service or access sensitive data. For example, an attacker could make the vLLM pod send malicious requests to an internal llm-d management endpoint, leading to system instability by falsely reporting metrics like the KV cache state.
Vulnerability Details
The core of the vulnerability lies in the MediaConnector.load_from_url method and its asynchronous counterpart. These methods accept a URL string to fetch media content (images, audio, video).
https://github.com/vllm-project/vllm/blob/119f683949dfed10df769fe63b2676d7f1eb644e/vllm/multimodal/utils.py#L97-L113
The function directly processes URLs with http, https, and file schemes. An attacker can supply a URL pointing to an internal IP address or a localhost endpoint. The vLLM server will then initiate a connection to this internal resource.
- HTTP/HTTPS Scheme: An attacker can craft a request like
{"image_url": "http://127.0.0.1:8080/internal_api"}. The vLLM server will send a GET request to this internal endpoint. - File Scheme: The
_load_file_urlmethod attempts to restrict file access to a subdirectory defined by--allowed-local-media-path. While this is a good security measure for local file access, it does not prevent network-based SSRF attacks.
Impact in llm-d Environments
The risk is significantly amplified in orchestrated environments such as llm-d, where multiple pods communicate over an internal network.
-
Denial of Service (DoS): An attacker could target internal management endpoints of other services within the
llm-dcluster. For instance, if a monitoring or metrics service is exposed internally, an attacker could send malformed requests to it. A specific example is an attacker causing the vLLM pod to call an internal API that reports a false KV cache utilization, potentially triggering incorrect scaling decisions or even a system shutdown. -
Internal Network Reconnaissance: Attackers can use the vulnerability to scan the internal network for open ports and services by providing URLs like
http://10.0.0.X:PORTand observing the server's response time or error messages. -
Interaction with Internal Services: Any unsecured internal service becomes a potential target. This could include databases, internal APIs, or other model pods that might not have robust authentication, as they are not expected to be directly exposed.
Delegating this security responsibility to an upper-level orchestrator like llm-d is problematic. The orchestrator cannot easily distinguish between legitimate requests initiated by the vLLM engine for its own purposes and malicious requests originating from user input, thus complicating traffic filtering rules and increasing management overhead.
Fix
See the --allowed-media-domains option discussed here: https://docs.vllm.ai/en/latest/usage/security.html#4-restrict-domains-access-for-media-urls
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "vllm"
},
"ranges": [
{
"events": [
{
"introduced": "0.5.0"
},
{
"fixed": "0.11.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-6242"
],
"database_specific": {
"cwe_ids": [
"CWE-601",
"CWE-918"
],
"github_reviewed": true,
"github_reviewed_at": "2025-10-07T22:14:15Z",
"nvd_published_at": "2025-10-07T20:15:36Z",
"severity": "HIGH"
},
"details": "### Summary\n\nA Server-Side Request Forgery (SSRF) vulnerability exists in the `MediaConnector` class within the vLLM project\u0027s multimodal feature set. The `load_from_url` and `load_from_url_async` methods fetch and process media from user-provided URLs without adequate restrictions on the target hosts. This allows an attacker to coerce the vLLM server into making arbitrary requests to internal network resources.\n\nThis vulnerability is particularly critical in containerized environments like `llm-d`, where a compromised vLLM pod could be used to scan the internal network, interact with other pods, and potentially cause denial of service or access sensitive data. For example, an attacker could make the vLLM pod send malicious requests to an internal `llm-d` management endpoint, leading to system instability by falsely reporting metrics like the KV cache state.\n\n### Vulnerability Details\n\nThe core of the vulnerability lies in the `MediaConnector.load_from_url` method and its asynchronous counterpart. These methods accept a URL string to fetch media content (images, audio, video).\n\nhttps://github.com/vllm-project/vllm/blob/119f683949dfed10df769fe63b2676d7f1eb644e/vllm/multimodal/utils.py#L97-L113\n\nThe function directly processes URLs with `http`, `https`, and `file` schemes. An attacker can supply a URL pointing to an internal IP address or a `localhost` endpoint. The vLLM server will then initiate a connection to this internal resource.\n\n* **HTTP/HTTPS Scheme:** An attacker can craft a request like `{\"image_url\": \"http://127.0.0.1:8080/internal_api\"}`. The vLLM server will send a GET request to this internal endpoint.\n* **File Scheme:** The `_load_file_url` method attempts to restrict file access to a subdirectory defined by `--allowed-local-media-path`. While this is a good security measure for local file access, it does not prevent network-based SSRF attacks.\n\n### Impact in `llm-d` Environments\n\nThe risk is significantly amplified in orchestrated environments such as `llm-d`, where multiple pods communicate over an internal network.\n\n1. **Denial of Service (DoS):** An attacker could target internal management endpoints of other services within the `llm-d` cluster. For instance, if a monitoring or metrics service is exposed internally, an attacker could send malformed requests to it. A specific example is an attacker causing the vLLM pod to call an internal API that reports a false KV cache utilization, potentially triggering incorrect scaling decisions or even a system shutdown.\n\n2. **Internal Network Reconnaissance:** Attackers can use the vulnerability to scan the internal network for open ports and services by providing URLs like `http://10.0.0.X:PORT` and observing the server\u0027s response time or error messages.\n\n3. **Interaction with Internal Services:** Any unsecured internal service becomes a potential target. This could include databases, internal APIs, or other model pods that might not have robust authentication, as they are not expected to be directly exposed.\n\nDelegating this security responsibility to an upper-level orchestrator like `llm-d` is problematic. **The orchestrator cannot easily distinguish between legitimate requests initiated by the vLLM engine for its own purposes and malicious requests originating from user input, thus complicating traffic filtering rules and increasing management overhead.**\n\n### Fix\n\nSee the `--allowed-media-domains` option discussed here: https://docs.vllm.ai/en/latest/usage/security.html#4-restrict-domains-access-for-media-urls",
"id": "GHSA-3f6c-7fw2-ppm4",
"modified": "2025-10-27T20:00:22Z",
"published": "2025-10-07T22:14:15Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/vllm-project/vllm/security/advisories/GHSA-3f6c-7fw2-ppm4"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-6242"
},
{
"type": "WEB",
"url": "https://github.com/vllm-project/vllm/commit/9d9a2b77f19f68262d5e469c4e82c0f6365ad72d"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2025-6242"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2373716"
},
{
"type": "PACKAGE",
"url": "https://github.com/vllm-project/vllm"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:H",
"type": "CVSS_V3"
}
],
"summary": "vLLM is vulnerable to Server-Side Request Forgery (SSRF) through `MediaConnector` class"
}
GHSA-3F9Q-JJQQ-4G32
Vulnerability from github – Published: 2022-05-17 02:40 – Updated: 2022-05-17 02:40An open redirect vulnerability is present in Piwigo 2.9 and probably prior versions, allowing remote attackers to redirect users to arbitrary web sites and conduct phishing attacks. The identification.php component is affected by this issue: the "redirect" parameter is not validated.
{
"affected": [],
"aliases": [
"CVE-2017-9464"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-06-14T19:29:00Z",
"severity": "MODERATE"
},
"details": "An open redirect vulnerability is present in Piwigo 2.9 and probably prior versions, allowing remote attackers to redirect users to arbitrary web sites and conduct phishing attacks. The identification.php component is affected by this issue: the \"redirect\" parameter is not validated.",
"id": "GHSA-3f9q-jjqq-4g32",
"modified": "2022-05-17T02:40:52Z",
"published": "2022-05-17T02:40:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-9464"
},
{
"type": "WEB",
"url": "https://github.com/Piwigo/Piwigo/issues/706"
},
{
"type": "WEB",
"url": "https://www.wizlynxgroup.com/security-research-advisories/vuln/WLX-2017-007"
}
],
"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-3FJ7-9J8M-7R8G
Vulnerability from github – Published: 2022-05-13 01:31 – Updated: 2024-01-26 18:27A vulnerability was found in moodle before versions 3.6.3, 3.5.5, 3.4.8 and 3.1.17. Links within assignment submission comments would open directly (in the same window). Although links themselves may be valid, opening within the same window and without the no-referrer header policy made them more susceptible to exploits.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "moodle/moodle"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.1.17"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "moodle/moodle"
},
"ranges": [
{
"events": [
{
"introduced": "3.2.0"
},
{
"fixed": "3.4.8"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "moodle/moodle"
},
"ranges": [
{
"events": [
{
"introduced": "3.5.0"
},
{
"fixed": "3.5.5"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "moodle/moodle"
},
"ranges": [
{
"events": [
{
"introduced": "3.6.0"
},
{
"fixed": "3.6.3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2019-3850"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2024-01-26T18:27:22Z",
"nvd_published_at": "2019-03-26T18:29:00Z",
"severity": "MODERATE"
},
"details": "A vulnerability was found in moodle before versions 3.6.3, 3.5.5, 3.4.8 and 3.1.17. Links within assignment submission comments would open directly (in the same window). Although links themselves may be valid, opening within the same window and without the no-referrer header policy made them more susceptible to exploits.",
"id": "GHSA-3fj7-9j8m-7r8g",
"modified": "2024-01-26T18:27:22Z",
"published": "2022-05-13T01:31:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2019-3850"
},
{
"type": "WEB",
"url": "https://github.com/moodle/moodle/commit/1fc481dd7b09e08e85824c1fe6733b303a36bdce"
},
{
"type": "WEB",
"url": "https://github.com/moodle/moodle/commit/772c908d40a944efd91d897d524b255626d330d4"
},
{
"type": "WEB",
"url": "https://github.com/moodle/moodle/commit/907b377e51c32ea37feef53e10684b504e103273"
},
{
"type": "WEB",
"url": "https://github.com/moodle/moodle/commit/d3f2f990dd3c5d4e6073a77154c6423d1c304647"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3850"
},
{
"type": "PACKAGE",
"url": "https://github.com/moodle/moodle"
},
{
"type": "WEB",
"url": "https://moodle.org/mod/forum/discuss.php?d=384013#p1547745"
}
],
"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"
}
],
"summary": "Moodle Stored HTML in assignment submission comments allowed links to be opened directly"
}
GHSA-3G24-RV7H-5XH5
Vulnerability from github – Published: 2022-10-11 12:00 – Updated: 2022-10-11 19:00An HTML injection vulnerability exists in CERT/CC VINCE software prior to 1.50.4. An authenticated attacker can inject arbitrary HTML via a crafted email with HTML content in the Subject field.
{
"affected": [],
"aliases": [
"CVE-2022-40257"
],
"database_specific": {
"cwe_ids": [
"CWE-601",
"CWE-74",
"CWE-79"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-10-10T20:15:00Z",
"severity": "MODERATE"
},
"details": "An HTML injection vulnerability exists in CERT/CC VINCE software prior to 1.50.4. An authenticated attacker can inject arbitrary HTML via a crafted email with HTML content in the Subject field.",
"id": "GHSA-3g24-rv7h-5xh5",
"modified": "2022-10-11T19:00:26Z",
"published": "2022-10-11T12:00:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-40257"
},
{
"type": "WEB",
"url": "https://github.com/CERTCC/VINCE/issues?q=label%3Asecurity"
}
],
"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"
}
]
}
GHSA-3GHF-CHW5-4MXM
Vulnerability from github – Published: 2022-05-14 01:57 – Updated: 2022-05-14 01:57The Feed Statistics plugin before 4.0 for WordPress has an Open Redirect via the feed-stats-url parameter.
{
"affected": [],
"aliases": [
"CVE-2018-17074"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-09-16T02:29:00Z",
"severity": "MODERATE"
},
"details": "The Feed Statistics plugin before 4.0 for WordPress has an Open Redirect via the feed-stats-url parameter.",
"id": "GHSA-3ghf-chw5-4mxm",
"modified": "2022-05-14T01:57:00Z",
"published": "2022-05-14T01:57:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-17074"
},
{
"type": "WEB",
"url": "https://hackerone.com/reports/22142"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/wordpress-feed-statistics/trunk/feed-statistics.php?rev=960868"
},
{
"type": "WEB",
"url": "https://wordpress.org/plugins/wordpress-feed-statistics/#developers"
},
{
"type": "WEB",
"url": "https://wpvulndb.com/vulnerabilities/7543"
}
],
"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-3GJC-QGPJ-P9MW
Vulnerability from github – Published: 2022-05-24 19:14 – Updated: 2022-05-24 19:14Open Redirection vulnerability in NetIQ Access Manager prior to 5.0.1 and 4.5.4
{
"affected": [],
"aliases": [
"CVE-2021-22526"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-09-13T12:15:00Z",
"severity": "MODERATE"
},
"details": "Open Redirection vulnerability in NetIQ Access Manager prior to 5.0.1 and 4.5.4",
"id": "GHSA-3gjc-qgpj-p9mw",
"modified": "2022-05-24T19:14:21Z",
"published": "2022-05-24T19:14:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-22526"
},
{
"type": "WEB",
"url": "https://support.microfocus.com/kb/doc.php?id=7025257"
},
{
"type": "WEB",
"url": "https://www.microfocus.com/documentation/access-manager/5.0/accessmanager501-release-notes/accessmanager501-release-notes.html"
}
],
"schema_version": "1.4.0",
"severity": []
}
Mitigation MIT-5
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. Reject any input that does not strictly conform to specifications, or transform it into something that does.
- 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.
- Use a list of approved URLs or domains to be used for redirection.
Mitigation
Use an intermediate disclaimer page that provides the user with a clear warning that they are leaving the current site. Implement a long timeout before the redirect occurs, or force the user to click on the link. Be careful to avoid XSS problems (CWE-79) when generating the disclaimer page.
Mitigation MIT-21.2
Strategy: Enforcement by Conversion
- When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
- For example, ID 1 could map to "/login.asp" and ID 2 could map to "http://www.example.com/". Features such as the ESAPI AccessReferenceMap [REF-45] provide this capability.
Mitigation
Ensure that no externally-supplied requests are honored by requiring that all redirect requests include a unique nonce generated by the application [REF-483]. Be sure that the nonce is not predictable (CWE-330).
Mitigation MIT-6
Strategy: Attack Surface Reduction
- Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
- Many open redirect problems occur because the programmer assumed that certain inputs could not be modified, such as cookies and hidden form fields.
Mitigation MIT-29
Strategy: Firewall
Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
CAPEC-178: Cross-Site Flashing
An attacker is able to trick the victim into executing a Flash document that passes commands or calls to a Flash player browser plugin, allowing the attacker to exploit native Flash functionality in the client browser. This attack pattern occurs where an attacker can provide a crafted link to a Flash document (SWF file) which, when followed, will cause additional malicious instructions to be executed. The attacker does not need to serve or control the Flash document. The attack takes advantage of the fact that Flash files can reference external URLs. If variables that serve as URLs that the Flash application references can be controlled through parameters, then by creating a link that includes values for those parameters, an attacker can cause arbitrary content to be referenced and possibly executed by the targeted Flash application.