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.
2307 vulnerabilities reference this CWE, most recent first.
GHSA-5WRH-4JWV-5W78
Vulnerability from github – Published: 2021-04-13 15:13 – Updated: 2024-09-30 20:28Impact
Requests to user provided domains were not restricted to external IP addresses when transitional IPv6 addresses were used. Outbound requests to federation, identity servers, when calculating the key validity for third-party invite events, sending push notifications, and generating URL previews are affected. This could cause Synapse to make requests to internal infrastructure on dual-stack networks.
Patches
This issue is fixed by #9240.
Workarounds
Outbound requests to the following address ranges can be blocked by a firewall, if unused for internal communication between systems:
::ffff/80::0000/80(note that this IP range is considered deprecated by the IETF)2002::/16(note that this IP range is considered deprecated by the IETF)
References
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "matrix-synapse"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.28.0rc1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-21392"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2021-04-12T21:51:49Z",
"nvd_published_at": "2021-04-12T22:15:00Z",
"severity": "HIGH"
},
"details": "### Impact\nRequests to user provided domains were not restricted to external IP addresses when transitional IPv6 addresses were used. Outbound requests to federation, identity servers, when calculating the key validity for third-party invite events, sending push notifications, and generating URL previews are affected. This could cause Synapse to make requests to internal infrastructure on dual-stack networks.\n\n### Patches\nThis issue is fixed by #9240.\n\n### Workarounds\nOutbound requests to the following address ranges can be blocked by a firewall, if unused for internal communication between systems:\n\n* `::ffff/80`\n* `::0000/80` (note that this IP range is considered deprecated by the IETF)\n* `2002::/16` (note that this IP range is considered deprecated by the IETF)\n\n### References\n* [RFC3056](https://tools.ietf.org/html/rfc3056)\n* [RFC4291](https://tools.ietf.org/html/rfc4291)",
"id": "GHSA-5wrh-4jwv-5w78",
"modified": "2024-09-30T20:28:18Z",
"published": "2021-04-13T15:13:08Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-5wrh-4jwv-5w78"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-21392"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/synapse/pull/9240"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/synapse/commit/4ca054a4eaa714d0befb4fc30b19a1131e52c9cc"
},
{
"type": "PACKAGE",
"url": "https://github.com/matrix-org/synapse"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2021-25.yaml"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY"
},
{
"type": "WEB",
"url": "https://pypi.org/project/matrix-synapse"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Open redirect via transitional IPv6 addresses on dual-stack networks"
}
GHSA-5WV4-GXJ7-WPQW
Vulnerability from github – Published: 2022-03-29 00:01 – Updated: 2022-04-09 00:01** UNSUPPORTED WHEN ASSIGNED ** A vulnerability was found in Netegrity SiteMinder up to 4.5.1 and classified as critical. Affected by this issue is the file /siteminderagent/pwcgi/smpwservicescgi.exe of the component Login. The manipulation of the argument target leads to an open redirect. The exploit has been disclosed to the public and may be used. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
{
"affected": [],
"aliases": [
"CVE-2005-10001"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-03-28T21:15:00Z",
"severity": "MODERATE"
},
"details": "** UNSUPPORTED WHEN ASSIGNED ** A vulnerability was found in Netegrity SiteMinder up to 4.5.1 and classified as critical. Affected by this issue is the file /siteminderagent/pwcgi/smpwservicescgi.exe of the component Login. The manipulation of the argument target leads to an open redirect. The exploit has been disclosed to the public and may be used. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.",
"id": "GHSA-5wv4-gxj7-wpqw",
"modified": "2022-04-09T00:01:01Z",
"published": "2022-03-29T00:01:08Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2005-10001"
},
{
"type": "WEB",
"url": "https://vuldb.com/?id.1022"
}
],
"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-5WVV-Q5FV-2388
Vulnerability from github – Published: 2022-12-30 16:57 – Updated: 2022-12-30 16:57When hyper-staticfile performs a redirect for a directory request (e.g. a request for /dir that redirects to /dir/), the Location header value was derived from user input (the request path), simply appending a slash. The intent was to perform an origin-relative redirect, but specific inputs allowed performing a scheme-relative redirect instead.
An attacker could craft a special URL that would appear to be for the correct domain, but immediately redirects to a malicious domain. Such a URL can benefit phishing attacks, for example an innocent looking link in an email.
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "hyper-staticfile"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.9.4"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "crates.io",
"name": "hyper-staticfile"
},
"ranges": [
{
"events": [
{
"introduced": "0.10.0-alpha.1"
},
{
"fixed": "0.10.0-alpha.5"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2022-12-30T16:57:28Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "When `hyper-staticfile` performs a redirect for a directory request (e.g. a request for `/dir` that redirects to `/dir/`), the `Location` header value was derived from user input (the request path), simply appending a slash. The intent was to perform an origin-relative redirect, but specific inputs allowed performing a scheme-relative redirect instead.\n\nAn attacker could craft a special URL that would appear to be for the correct domain, but immediately redirects to a malicious domain. Such a URL can benefit phishing attacks, for example an innocent looking link in an email.\n",
"id": "GHSA-5wvv-q5fv-2388",
"modified": "2022-12-30T16:57:28Z",
"published": "2022-12-30T16:57:28Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/stephank/hyper-staticfile/commit/4db4afb811c553bc3d54a01a9985b9e6dfc5a115"
},
{
"type": "WEB",
"url": "https://github.com/stephank/hyper-staticfile/commit/f12cadc6666c6f555d29725f5bc45da2103f24ea"
},
{
"type": "PACKAGE",
"url": "https://github.com/stephank/hyper-staticfile"
},
{
"type": "WEB",
"url": "https://rustsec.org/advisories/RUSTSEC-2022-0072.html"
}
],
"schema_version": "1.4.0",
"severity": [],
"summary": "hyper-staticfile\u0027s location header incorporates user input, allowing open redirect"
}
GHSA-5WW2-V6PW-8XX5
Vulnerability from github – Published: 2022-05-13 01:37 – Updated: 2022-05-13 01:37Multiple vulnerabilities in Cisco Data Center Network Manager (DCNM) Software could allow a remote attacker to inject arbitrary values into DCNM configuration parameters, redirect a user to a malicious website, inject malicious content into a DCNM client interface, or conduct a cross-site scripting (XSS) attack against a user of the affected software. Cisco Bug IDs: CSCvf40477, CSCvf63150, CSCvf68218, CSCvf68235, CSCvf68247.
{
"affected": [],
"aliases": [
"CVE-2017-12344"
],
"database_specific": {
"cwe_ids": [
"CWE-601",
"CWE-79"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-11-30T09:29:00Z",
"severity": "MODERATE"
},
"details": "Multiple vulnerabilities in Cisco Data Center Network Manager (DCNM) Software could allow a remote attacker to inject arbitrary values into DCNM configuration parameters, redirect a user to a malicious website, inject malicious content into a DCNM client interface, or conduct a cross-site scripting (XSS) attack against a user of the affected software. Cisco Bug IDs: CSCvf40477, CSCvf63150, CSCvf68218, CSCvf68235, CSCvf68247.",
"id": "GHSA-5ww2-v6pw-8xx5",
"modified": "2022-05-13T01:37:50Z",
"published": "2022-05-13T01:37:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-12344"
},
{
"type": "WEB",
"url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20171129-dcnm"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/101996"
}
],
"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-5XP2-RV4H-MM2Q
Vulnerability from github – Published: 2022-05-24 16:48 – Updated: 2024-01-26 18:04A flaw was found in Moodle before 3.7, 3.6.4, 3.5.6, 3.4.9 and 3.1.18. The form to upload cohorts contained a redirect field, which was not restricted to internal URLs.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 3.6.3"
},
"package": {
"ecosystem": "Packagist",
"name": "moodle/moodle"
},
"ranges": [
{
"events": [
{
"introduced": "3.6.0"
},
{
"fixed": "3.6.4"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 3.5.5"
},
"package": {
"ecosystem": "Packagist",
"name": "moodle/moodle"
},
"ranges": [
{
"events": [
{
"introduced": "3.5.0"
},
{
"fixed": "3.5.6"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 3.4.8"
},
"package": {
"ecosystem": "Packagist",
"name": "moodle/moodle"
},
"ranges": [
{
"events": [
{
"introduced": "3.4.0"
},
{
"fixed": "3.4.9"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 3.1.17"
},
"package": {
"ecosystem": "Packagist",
"name": "moodle/moodle"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.1.18"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2019-10133"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2023-08-01T23:29:14Z",
"nvd_published_at": "2019-06-26T19:15:00Z",
"severity": "MODERATE"
},
"details": "A flaw was found in Moodle before 3.7, 3.6.4, 3.5.6, 3.4.9 and 3.1.18. The form to upload cohorts contained a redirect field, which was not restricted to internal URLs.",
"id": "GHSA-5xp2-rv4h-mm2q",
"modified": "2024-01-26T18:04:42Z",
"published": "2022-05-24T16:48:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2019-10133"
},
{
"type": "WEB",
"url": "https://github.com/moodle/moodle/commit/5a89ac9640b3a695720845b6ddeff65e69a289fc"
},
{
"type": "WEB",
"url": "https://github.com/moodle/moodle/commit/a6258d0934f707b1d033f50fb41ffbcf45bb2102"
},
{
"type": "WEB",
"url": "https://github.com/moodle/moodle/commit/c509d108216524887c7ca08b1c451054d669ea75"
},
{
"type": "WEB",
"url": "https://github.com/moodle/moodle/commit/cd6fb4322b6b1914c05f05033a71ed060f875fd4"
},
{
"type": "WEB",
"url": "https://github.com/moodle/moodle/commit/d5067bffd230d733ad24f6aeaa56aaa17eca5bfb"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-10133"
},
{
"type": "PACKAGE",
"url": "https://github.com/moodle/moodle"
},
{
"type": "WEB",
"url": "https://moodle.org/mod/forum/discuss.php?d=386523"
}
],
"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 Open Redirect Vulnerability"
}
GHSA-5XP8-7CCH-3599
Vulnerability from github – Published: 2025-12-16 18:31 – Updated: 2025-12-16 18:31WBCE CMS 1.6.1 contains a cross-site scripting vulnerability that allows attackers to inject malicious HTML and CSS to capture user keystrokes. Attackers can upload a crafted HTML file with CSS-based keylogging techniques to intercept password characters through background image requests.
{
"affected": [],
"aliases": [
"CVE-2023-53901"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-16T17:16:02Z",
"severity": "HIGH"
},
"details": "WBCE CMS 1.6.1 contains a cross-site scripting vulnerability that allows attackers to inject malicious HTML and CSS to capture user keystrokes. Attackers can upload a crafted HTML file with CSS-based keylogging techniques to intercept password characters through background image requests.",
"id": "GHSA-5xp8-7cch-3599",
"modified": "2025-12-16T18:31:34Z",
"published": "2025-12-16T18:31:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-53901"
},
{
"type": "WEB",
"url": "https://wbce-cms.org"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/51566"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/wbce-cms-cross-site-scripting-and-open-redirect-vulnerability"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/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-624F-CQVR-3QW4
Vulnerability from github – Published: 2021-09-08 21:11 – Updated: 2025-03-07 19:09Impact
If using Flask-AppBuilder OAuth, an attacker can share a carefully crafted URL with a trusted domain for an application built with Flask-AppBuilder, this URL can redirect a user to a malicious site. This is an open redirect vulnerability
Patches
Install Flask-AppBuilder 3.2.2 or above
Workarounds
Filter HTTP traffic containing ?next={next-site} where the next-site domain is different from the application you are protecting
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "Flask-AppBuilder"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.3.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-32805"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2021-09-08T21:10:56Z",
"nvd_published_at": "2021-09-08T18:15:00Z",
"severity": "MODERATE"
},
"details": "### Impact\nIf using Flask-AppBuilder OAuth, an attacker can share a carefully crafted URL with a trusted domain for an application built with Flask-AppBuilder, this URL can redirect a user to a malicious site. This is an open redirect vulnerability \n\n### Patches\nInstall Flask-AppBuilder 3.2.2 or above\n\n### Workarounds\nFilter HTTP traffic containing `?next={next-site}` where the `next-site` domain is different from the application you are protecting",
"id": "GHSA-624f-cqvr-3qw4",
"modified": "2025-03-07T19:09:11Z",
"published": "2021-09-08T21:11:14Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/dpgaspar/Flask-AppBuilder/security/advisories/GHSA-624f-cqvr-3qw4"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-32805"
},
{
"type": "WEB",
"url": "https://github.com/dpgaspar/Flask-AppBuilder/commit/6af28521589599b1dbafd6313256229ee9a4fa74"
},
{
"type": "PACKAGE",
"url": "https://github.com/dpgaspar/Flask-AppBuilder"
},
{
"type": "WEB",
"url": "https://github.com/dpgaspar/Flask-AppBuilder/releases/tag/v3.3.2"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/flask-appbuilder/PYSEC-2021-359.yaml"
},
{
"type": "WEB",
"url": "https://pypi.org/project/Flask-AppBuilder"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Flask-AppBuilder Open Redirect vulnerability"
}
GHSA-62F9-V4FV-RW5H
Vulnerability from github – Published: 2023-10-04 09:30 – Updated: 2023-10-04 09:30Open Redirect in GitHub repository mosparo/mosparo prior to 1.0.2.
{
"affected": [],
"aliases": [
"CVE-2023-5375"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-10-04T09:15:31Z",
"severity": "MODERATE"
},
"details": "Open Redirect in GitHub repository mosparo/mosparo prior to 1.0.2.",
"id": "GHSA-62f9-v4fv-rw5h",
"modified": "2023-10-04T09:30:20Z",
"published": "2023-10-04T09:30:20Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-5375"
},
{
"type": "WEB",
"url": "https://github.com/mosparo/mosparo/commit/9d5da367b78b8c883bfef5f332ffea26292f99e8"
},
{
"type": "WEB",
"url": "https://huntr.dev/bounties/3fa2abde-cb58-45a3-a115-1727ece9acb9"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-62GH-Q5G8-JV59
Vulnerability from github – Published: 2024-08-01 18:32 – Updated: 2025-05-20 09:30The Identity Server used by 1E Platform could enable URL redirection to untrusted sites. Note: The Identity Server on 1E Platform has been updated with the necessary patch.
{
"affected": [],
"aliases": [
"CVE-2024-7211"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-08-01T17:16:09Z",
"severity": "MODERATE"
},
"details": "The Identity Server used by 1E Platform could enable URL redirection to untrusted sites.\nNote: The Identity Server on 1E Platform has been updated with the necessary patch.",
"id": "GHSA-62gh-q5g8-jv59",
"modified": "2025-05-20T09:30:59Z",
"published": "2024-08-01T18:32:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-7211"
},
{
"type": "WEB",
"url": "https://www.1e.com/trust-security-compliance/cve-info"
},
{
"type": "WEB",
"url": "https://www.teamviewer.com/en/resources/trust-center/security-bulletins/1e-2024-2001"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-6376-C738-938M
Vulnerability from github – Published: 2022-05-14 02:01 – Updated: 2022-05-14 02:01Insufficient policy enforcement in Resource Timing API in Google Chrome prior to 63.0.3239.84 allowed a remote attacker to infer browsing history by triggering a leaked cross-origin URL via a crafted HTML page.
{
"affected": [],
"aliases": [
"CVE-2017-15419"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-08-28T19:29:00Z",
"severity": "MODERATE"
},
"details": "Insufficient policy enforcement in Resource Timing API in Google Chrome prior to 63.0.3239.84 allowed a remote attacker to infer browsing history by triggering a leaked cross-origin URL via a crafted HTML page.",
"id": "GHSA-6376-c738-938m",
"modified": "2022-05-14T02:01:47Z",
"published": "2022-05-14T02:01:47Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-15419"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2017:3401"
},
{
"type": "WEB",
"url": "https://chromereleases.googleblog.com/2017/12/stable-channel-update-for-desktop.html"
},
{
"type": "WEB",
"url": "https://crbug.com/780312"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/201801-03"
},
{
"type": "WEB",
"url": "https://www.debian.org/security/2017/dsa-4064"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
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.