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.
2336 vulnerabilities reference this CWE, most recent first.
GHSA-CRV8-J8M6-H7PQ
Vulnerability from github – Published: 2022-05-24 17:30 – Updated: 2022-05-24 17:30IProom MMC+ Server login page does not validate specific parameters properly. Attackers can use the vulnerability to redirect to any malicious site and steal the victim's login credentials.
{
"affected": [],
"aliases": [
"CVE-2020-24551"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-10-14T13:15:00Z",
"severity": "MODERATE"
},
"details": "IProom MMC+ Server login page does not validate specific parameters properly. Attackers can use the vulnerability to redirect to any malicious site and steal the victim\u0027s login credentials.",
"id": "GHSA-crv8-j8m6-h7pq",
"modified": "2022-05-24T17:30:39Z",
"published": "2022-05-24T17:30:39Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-24551"
},
{
"type": "WEB",
"url": "https://www.twcert.org.tw/tw/cp-132-4053-6e9a2-1.html"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-CRXJ-HRMP-4RWF
Vulnerability from github – Published: 2022-09-29 00:00 – Updated: 2022-09-30 06:31Labstack Echo v4.8.0 was discovered to contain an open redirect vulnerability via the Static Handler component. This vulnerability can be leveraged by attackers to cause a Server-Side Request Forgery (SSRF). Version 4.9.0 contains a patch for the issue.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/labstack/echo/v4"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.9.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2022-40083"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2022-09-30T06:31:20Z",
"nvd_published_at": "2022-09-28T14:15:00Z",
"severity": "CRITICAL"
},
"details": "Labstack Echo v4.8.0 was discovered to contain an open redirect vulnerability via the Static Handler component. This vulnerability can be leveraged by attackers to cause a Server-Side Request Forgery (SSRF). Version 4.9.0 contains a patch for the issue.",
"id": "GHSA-crxj-hrmp-4rwf",
"modified": "2022-09-30T06:31:20Z",
"published": "2022-09-29T00:00:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-40083"
},
{
"type": "WEB",
"url": "https://github.com/labstack/echo/issues/2259"
},
{
"type": "WEB",
"url": "https://github.com/labstack/echo/pull/2260"
},
{
"type": "WEB",
"url": "https://github.com/labstack/echo/pull/2260/commits/3154abd1401554fe4d1c09ec550506d8625fc042"
},
{
"type": "WEB",
"url": "https://github.com/labstack/echo/commit/0ac4d74402391912ff6da733bb09fd4c3980b4e1"
},
{
"type": "PACKAGE",
"url": "https://github.com/labstack/echo"
},
{
"type": "WEB",
"url": "https://github.com/labstack/echo/releases/tag/v4.9.0"
},
{
"type": "WEB",
"url": "https://pkg.go.dev/vuln/GO-2022-1031"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Labstack Echo Open Redirect vulnerability"
}
GHSA-CV26-8GJ7-XP72
Vulnerability from github – Published: 2024-01-03 03:30 – Updated: 2025-06-03 15:31HCL DRYiCE MyXalytics is impacted by an Open Redirect vulnerability which could allow an attacker to redirect users to malicious sites, potentially leading to phishing attacks or other security threats.
{
"affected": [],
"aliases": [
"CVE-2023-50345"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-01-03T02:15:43Z",
"severity": "LOW"
},
"details": "HCL DRYiCE MyXalytics is impacted by an Open Redirect vulnerability which could allow an attacker to redirect users to malicious sites, potentially leading to phishing attacks or other security threats.",
"id": "GHSA-cv26-8gj7-xp72",
"modified": "2025-06-03T15:31:02Z",
"published": "2024-01-03T03:30:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-50345"
},
{
"type": "WEB",
"url": "https://support.hcltechsw.com/csm?id=kb_article\u0026sysparm_article=KB0109608"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-CV3H-4JH6-RH6P
Vulnerability from github – Published: 2024-07-17 18:31 – Updated: 2024-07-17 18:31A vulnerability in the web-based management interface of Cisco Expressway Series could allow an unauthenticated, remote attacker to redirect a user to a malicious web page.
This vulnerability is due to improper input validation of HTTP request parameters. An attacker could exploit this vulnerability by intercepting and modifying an HTTP request from a user. A successful exploit could allow the attacker to redirect the user to a malicious web page.
Note: Cisco Expressway Series refers to Cisco Expressway Control (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.
{
"affected": [],
"aliases": [
"CVE-2024-20400"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-17T17:15:13Z",
"severity": "MODERATE"
},
"details": "A vulnerability in the web-based management interface of Cisco Expressway Series could allow an unauthenticated, remote attacker to redirect a user to a malicious web page.\n\n This vulnerability is due to improper input validation of HTTP request parameters. An attacker could exploit this vulnerability by intercepting and modifying an HTTP request from a user. A successful exploit could allow the attacker to redirect the user to a malicious web page.\n\n Note: Cisco Expressway Series refers to Cisco Expressway Control (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.",
"id": "GHSA-cv3h-4jh6-rh6p",
"modified": "2024-07-17T18:31:00Z",
"published": "2024-07-17T18:31:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-20400"
},
{
"type": "WEB",
"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-expressway-redirect-KJsFuXgj"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-CVFH-X2QQ-HW4Q
Vulnerability from github – Published: 2022-05-17 01:09 – Updated: 2022-05-17 01:09IBM Security Access Manager 6.1, 7.0, 8.0, and 9.0 e-community configurations may be affected by a redirect vulnerability. ECSSO Master Authentication can redirect to a server not participating in an e-community domain. IBM X-Force ID: 128687.
{
"affected": [],
"aliases": [
"CVE-2017-1489"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-08-29T01:35:00Z",
"severity": "MODERATE"
},
"details": "IBM Security Access Manager 6.1, 7.0, 8.0, and 9.0 e-community configurations may be affected by a redirect vulnerability. ECSSO Master Authentication can redirect to a server not participating in an e-community domain. IBM X-Force ID: 128687.",
"id": "GHSA-cvfh-x2qq-hw4q",
"modified": "2022-05-17T01:09:28Z",
"published": "2022-05-17T01:09:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-1489"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/128687"
},
{
"type": "WEB",
"url": "http://www.ibm.com/support/docview.wss?uid=swg22006959"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/100592"
},
{
"type": "WEB",
"url": "http://www.securitytracker.com/id/1039227"
}
],
"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-CVRM-5HP6-H523
Vulnerability from github – Published: 2026-05-15 16:21 – Updated: 2026-05-19 16:08Summary
The logout endpoint accepts a url query parameter to redirect to. casserver treats that url as trusted, and either (depending on configuration) redirects the browser there, or shows a "you've been logged out" page with a link to continue to that url.
There are a number of other things broken with logout in 7 (cas v3 uses a different query parameters, etc)
Details
https://github.com/simplesamlphp/simplesamlphp-module-casserver/blob/21418f7efbea8c4f078fd4a7d1b9eacf94dd4941/src/Controller/LogoutController.php#L104
Previous module checked the url against the valid service urls.
PoC
The docker instructions from the README.md run an image with a vulnerable config.
Accessing https://localhost/cas/logout?url=https://google.com will redirect to Google
Impact
Impacted configs have
'enable_logout' => true,
and are most impacted if they also have
'skip_logout_page' -> true,
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c 7.0.0-rc3"
},
"package": {
"ecosystem": "Packagist",
"name": "simplesamlphp/simplesamlphp-module-casserver"
},
"ranges": [
{
"events": [
{
"introduced": "7.0.0-rc1"
},
{
"fixed": "7.0.0"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Packagist",
"name": "simplesamlphp/simplesamlphp-module-casserver"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "6.3.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-65954"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2026-05-15T16:21:13Z",
"nvd_published_at": "2026-05-18T20:16:36Z",
"severity": "MODERATE"
},
"details": "### Summary\n\nThe logout endpoint accepts a `url` query parameter to redirect to. casserver treats that url as trusted, and either (depending on configuration) redirects the browser there, or shows a \"you\u0027ve been logged out\" page with a link to continue to that url.\n\nThere are a number of other things broken with logout in 7 (cas v3 uses a different query parameters, etc)\n\n### Details\n\nhttps://github.com/simplesamlphp/simplesamlphp-module-casserver/blob/21418f7efbea8c4f078fd4a7d1b9eacf94dd4941/src/Controller/LogoutController.php#L104\n\nPrevious module checked the url against the valid service urls.\n\n### PoC\n\nThe docker instructions from the README.md run an image with a vulnerable config. \n\nAccessing https://localhost/cas/logout?url=https://google.com will redirect to Google\n\n### Impact\n\nImpacted configs have\n\n```php\n\u0027enable_logout\u0027 =\u003e true,\n```\n\nand are most impacted if they also have\n\n```\n\u0027skip_logout_page\u0027 -\u003e true,\n```",
"id": "GHSA-cvrm-5hp6-h523",
"modified": "2026-05-19T16:08:50Z",
"published": "2026-05-15T16:21:13Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/simplesamlphp/simplesamlphp-module-casserver/security/advisories/GHSA-cvrm-5hp6-h523"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-65954"
},
{
"type": "WEB",
"url": "https://github.com/simplesamlphp/simplesamlphp-module-casserver/commit/0462f50f00b3bb300d83067d11b74146a57bb8e0"
},
{
"type": "WEB",
"url": "https://github.com/simplesamlphp/simplesamlphp-module-casserver/commit/fb6c6f1c7b9e757c93c5c306e1d36405e64f6dc5"
},
{
"type": "PACKAGE",
"url": "https://github.com/simplesamlphp/simplesamlphp-module-casserver"
},
{
"type": "WEB",
"url": "https://github.com/simplesamlphp/simplesamlphp-module-casserver/blob/21418f7efbea8c4f078fd4a7d1b9eacf94dd4941/src/Controller/LogoutController.php#L104"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "SimpleSAMLphp casserver: Open Redirect in logout"
}
GHSA-CWJV-MXFR-RRV9
Vulnerability from github – Published: 2024-09-26 18:31 – Updated: 2024-09-26 21:31A host header injection vulnerability in BookReviewLibrary 1.0 allows attackers to obtain the password reset token via user interaction with a crafted password reset link.
{
"affected": [],
"aliases": [
"CVE-2024-45981"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-09-26T17:15:04Z",
"severity": "HIGH"
},
"details": "A host header injection vulnerability in BookReviewLibrary 1.0 allows attackers to obtain the password reset token via user interaction with a crafted password reset link.",
"id": "GHSA-cwjv-mxfr-rrv9",
"modified": "2024-09-26T21:31:11Z",
"published": "2024-09-26T18:31:44Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-45981"
},
{
"type": "WEB",
"url": "https://github.com/soursec/CVEs/tree/main/CVE-2024-45981"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-CWPQ-RG22-433H
Vulnerability from github – Published: 2022-05-24 16:46 – Updated: 2024-04-04 00:43Odoo Version <= 8.0-20160726 and Version 9 is affected by: CWE-601: Open redirection. The impact is: obtain sensitive information (remote).
{
"affected": [],
"aliases": [
"CVE-2017-5871"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2019-05-22T20:29:00Z",
"severity": "MODERATE"
},
"details": "Odoo Version \u003c= 8.0-20160726 and Version 9 is affected by: CWE-601: Open redirection. The impact is: obtain sensitive information (remote).",
"id": "GHSA-cwpq-rg22-433h",
"modified": "2024-04-04T00:43:04Z",
"published": "2022-05-24T16:46:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-5871"
},
{
"type": "WEB",
"url": "https://sysdream.com/news/lab/2017-11-20-cve-2017-5871-odoo-url-redirection-to-distrusted-site-open-redirect"
},
{
"type": "WEB",
"url": "https://www.odoo.com"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-CWX8-767M-CWMV
Vulnerability from github – Published: 2022-05-14 03:23 – Updated: 2022-05-14 03:23Mediawiki before 1.28.1 / 1.27.2 / 1.23.16 contains a flaw where Special:Search allows redirects to any interwiki link.
{
"affected": [],
"aliases": [
"CVE-2017-0364"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-04-13T16:29:00Z",
"severity": "MODERATE"
},
"details": "Mediawiki before 1.28.1 / 1.27.2 / 1.23.16 contains a flaw where Special:Search allows redirects to any interwiki link.",
"id": "GHSA-cwx8-767m-cwmv",
"modified": "2022-05-14T03:23:51Z",
"published": "2022-05-14T03:23:51Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-0364"
},
{
"type": "WEB",
"url": "https://lists.wikimedia.org/pipermail/mediawiki-announce/2017-April/000207.html"
},
{
"type": "WEB",
"url": "https://phabricator.wikimedia.org/T122209"
},
{
"type": "WEB",
"url": "https://security-tracker.debian.org/tracker/CVE-2017-0364"
}
],
"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-CXJ8-GGF2-P57C
Vulnerability from github – Published: 2026-04-03 21:43 – Updated: 2026-04-03 21:43Summary
SignalK Server contains a code-level vulnerability in its OIDC login and logout handlers where the unvalidated HTTP Host header is used to construct the OAuth2 redirect_uri. Because the redirectUri configuration is silently unset by default, an attacker spoof the Host header to steal OAuth authorization codes and hijack user sessions in realistic deployments as The OIDC provider will then send the authorization code to whatever domain was injected.
The OIDC specification requires redirect_uri to be pre-registered and not derived from untrusted input. Constructing it from the Host header violates this requirement and introduces a trust boundary break. This risk is actively amplified by SignalK's official documentation, which instructs administrators to deploy an Nginx configuration that forwards the vulnerable Host header, exposing production environments.
Vulnerability Root Cause
Two factors combine to create this vulnerability:
Factor 1: redirectUri is optional with an unsafe fallback In types.ts:30, redirectUri is declared as optional
export interface OIDCConfig {
// ...
redirectUri?: string // ← Optional, no default value
// ...
}
The defaults in types.ts:175-185 do not include a redirectUri: never checks or warns about a missing redirectUri. This means a fully "valid" OIDC configuration can exist without redirectUri, silently activating the vulnerable fallback path.
export const OIDC_DEFAULTS: Omit<OIDCConfig, 'issuer' | 'clientId' | 'clientSecret'> = {
enabled: false,
scope: 'openid email profile',
defaultPermission: 'readonly',
autoCreateUsers: true,
providerName: 'SSO Login',
autoLogin: false
// ← No redirectUri default
}
Factor 2: Unsafe Host header usage in two locations Location 1 — Login handler in oidc-auth.ts:278-282:
const protocol = req.secure ? 'https' : 'http'
const host = req.get('host') // ← Attacker-controlled
const redirectUri =
oidcConfig.redirectUri || // ← Only safe if explicitly set
`${protocol}://${host}${skAuthPrefix}/oidc/callback` // ← Uses attacker's Host
This redirectUri flows into createAuthState() → buildAuthorizationUrl() → OIDC provider's redirect_uri parameter. The OIDC provider will then send the authorization code to whatever domain was injected.
Location 2 — Logout handler in oidc-auth.ts:513-515:
const protocol = req.secure ? 'https' : 'http'
const host = req.get('host') // ← Same pattern
const fullPostLogoutUri = `${protocol}://${host}${postLogoutRedirect}`
This constructs the post_logout_redirect_uri sent to the OIDC provider's end_session_endpoint, allowing an attacker to redirect the user to an attacker controlled domain after logout.
Official Documentation Enables the Attack
SignalK's own security documentation at docs/security.md:222-228 provides the recommended nginx reverse proxy configuration: The proxy_set_header Host $host; directive forwards the client-supplied Host header to the backend unmodified. Without this directive, nginx would replace the Host header with the upstream address (localhost:3000), which would neutralize the injection.
location / {
proxy_pass http://localhost:3000;
proxy_set_header X-Forwarded-For $remote_addr;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header Host $host; # ← Forwards client's Host header to SignalK
}
Administrators who follow the official documentation are directly enabling this vulnerability behind their reverse proxy.
Proof of Concept
Tested against SignalK Server v2.23.0 in Docker with OIDC enabled .
Step 1 — Send login request with injected Host header:
$response = Invoke-WebRequest -Uri "http://localhost:3000/signalk/v1/auth/oidc/login" -Headers @{"Host"="evil.com"} -MaximumRedirection 0 -ErrorAction SilentlyContinue -UseBasicParsing
Step 2: Decode and print the injected redirect URL
[uri]::UnescapeDataString($response.Headers.Location)
Impact
- Authorization Code Theft: The OIDC provider sends the OAuth authorization code to the attacker's domain instead of the legitimate server.
- Session Hijack: The attacker can exchange the stolen code for tokens and create a session as the victim user.
- Logout Redirect Hijack: The logout handler has the same pattern, allowing post-logout redirection to an attacker domain (phishing opportunity).
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "signalk-server"
},
"ranges": [
{
"events": [
{
"introduced": "2.20.0"
},
{
"fixed": "2.24.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-34083"
],
"database_specific": {
"cwe_ids": [
"CWE-346",
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-03T21:43:22Z",
"nvd_published_at": "2026-04-02T17:16:23Z",
"severity": "MODERATE"
},
"details": "## Summary\n\nSignalK Server contains a code-level vulnerability in its OIDC login and logout handlers where the unvalidated HTTP Host header is used to construct the OAuth2 redirect_uri. Because the redirectUri configuration is silently unset by default, an **attacker spoof the Host header** to steal OAuth authorization codes and hijack user sessions in realistic deployments as The OIDC provider will then send the authorization code to whatever domain was injected.\n\n_The OIDC specification requires redirect_uri to be pre-registered and not derived from untrusted input. Constructing it from the Host header violates this requirement and introduces a trust boundary break._\nThis risk is actively amplified by SignalK\u0027s official documentation, which instructs administrators to deploy an Nginx configuration that forwards the vulnerable Host header, exposing production environments.\n\n## Vulnerability Root Cause\n\nTwo factors combine to create this vulnerability:\n\n**Factor 1: redirectUri is optional with an unsafe fallback**\nIn types.ts:30, redirectUri is declared as optional\n```\nexport interface OIDCConfig {\n // ...\n redirectUri?: string // \u2190 Optional, no default value\n // ...\n}\n```\n\nThe defaults in types.ts:175-185 do not include a redirectUri: never checks or warns about a missing redirectUri. This means a fully \"valid\" OIDC configuration can exist without redirectUri, silently activating the vulnerable fallback path.\n```\nexport const OIDC_DEFAULTS: Omit\u003cOIDCConfig, \u0027issuer\u0027 | \u0027clientId\u0027 | \u0027clientSecret\u0027\u003e = {\n enabled: false,\n scope: \u0027openid email profile\u0027,\n defaultPermission: \u0027readonly\u0027,\n autoCreateUsers: true,\n providerName: \u0027SSO Login\u0027,\n autoLogin: false\n // \u2190 No redirectUri default\n}\n```\n\n**Factor 2: Unsafe Host header usage in two locations**\nLocation 1 \u2014 Login handler in oidc-auth.ts:278-282:\n```\nconst protocol = req.secure ? \u0027https\u0027 : \u0027http\u0027\nconst host = req.get(\u0027host\u0027) // \u2190 Attacker-controlled\nconst redirectUri =\n oidcConfig.redirectUri || // \u2190 Only safe if explicitly set\n `${protocol}://${host}${skAuthPrefix}/oidc/callback` // \u2190 Uses attacker\u0027s Host\n\n```\nThis redirectUri flows into createAuthState() \u2192 buildAuthorizationUrl() \u2192 OIDC provider\u0027s redirect_uri parameter. The OIDC provider will then send the authorization code to whatever domain was injected.\n\nLocation 2 \u2014 Logout handler in oidc-auth.ts:513-515:\n```\nconst protocol = req.secure ? \u0027https\u0027 : \u0027http\u0027\nconst host = req.get(\u0027host\u0027) // \u2190 Same pattern\nconst fullPostLogoutUri = `${protocol}://${host}${postLogoutRedirect}`\n```\nThis constructs the post_logout_redirect_uri sent to the OIDC provider\u0027s end_session_endpoint, allowing an attacker to redirect the user to an attacker controlled domain after logout.\n\n### Official Documentation Enables the Attack\n\nSignalK\u0027s own security documentation at docs/security.md:222-228 provides the recommended nginx reverse proxy configuration:\nThe proxy_set_header Host $host; directive forwards the client-supplied Host header to the backend unmodified. Without this directive, nginx would replace the Host header with the upstream address (localhost:3000), which would neutralize the injection.\n```\nlocation / {\n proxy_pass http://localhost:3000;\n proxy_set_header X-Forwarded-For $remote_addr;\n proxy_set_header X-Forwarded-Proto $scheme;\n proxy_set_header Host $host; # \u2190 Forwards client\u0027s Host header to SignalK\n}\n```\nAdministrators who follow the official documentation are directly enabling this vulnerability behind their reverse proxy.\n\n## Proof of Concept \nTested against SignalK Server v2.23.0 in Docker with OIDC enabled .\n\n**Step 1 \u2014 Send login request with injected Host header:**\n`$response = Invoke-WebRequest -Uri \"http://localhost:3000/signalk/v1/auth/oidc/login\" -Headers @{\"Host\"=\"evil.com\"} -MaximumRedirection 0 -ErrorAction SilentlyContinue -UseBasicParsing`\n\n**Step 2: Decode and print the injected redirect URL**\n`[uri]::UnescapeDataString($response.Headers.Location)\n`\n\u003cimg width=\"1259\" height=\"211\" alt=\"Screenshot 2026-03-25 171251\" src=\"https://github.com/user-attachments/assets/6e4a9655-639e-48c2-a7f0-06e17ad471ff\" /\u003e\n\n## Impact\n\n* **Authorization Code Theft:** The OIDC provider sends the OAuth authorization code to the attacker\u0027s domain instead of the legitimate server.\n* **Session Hijack:** The attacker can exchange the stolen code for tokens and create a session as the victim user.\n* **Logout Redirect Hijack:** The logout handler has the same pattern, allowing post-logout redirection to an attacker domain (phishing opportunity).",
"id": "GHSA-cxj8-ggf2-p57c",
"modified": "2026-04-03T21:43:22Z",
"published": "2026-04-03T21:43:22Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/SignalK/signalk-server/security/advisories/GHSA-cxj8-ggf2-p57c"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34083"
},
{
"type": "PACKAGE",
"url": "https://github.com/SignalK/signalk-server"
},
{
"type": "WEB",
"url": "https://github.com/SignalK/signalk-server/releases/tag/v2.24.0"
}
],
"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"
}
],
"summary": "Signal K Server: OAuth Authorization Code Theft via Unvalidated Host Header in OIDC Flow"
}
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.