CVE-2021-29456
MEDIUM
Published Apr 21, 20215y ago · Modified Jun 17, 20262w ago
5.4 CVSS 3.1
Published Apr 21, 2021 5y ago
Last Modified Jun 17, 2026 2w ago
Description
Authelia is an open-source authentication and authorization server providing 2-factor authentication and single sign-on (SSO) for your applications via a web portal. In versions 4.27.4 and earlier, utilizing a HTTP query parameter an attacker is able to redirect users from the web application to any domain, including potentially malicious sites. This security issue does not directly impact the security of the web application itself. As a workaround, one can use a reverse proxy to strip the query parameter from the affected endpoint. There is a patch for version 4.28.0.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction Required
Scope Changed
Confidentiality Low
Integrity Low
Availability None
Threat Intelligence
No active exploitation signals — not in CISA KEV and no EPSS score yet.
Exploit & Patch Status
No Known Exploit
Patch Available
Weaknesses 1
CWE-601
Affected Products 1
| Vendor | Product | Version | Range |
|---|---|---|---|
| authelia | authelia | * | <4.28.0 |
References 1
- github.com https://github.com/authelia/authelia/security/advisories/GHSA-36f2-fcrx-fp4j
Remediation
- github.com https://github.com/authelia/authelia/security/advisories/GHSA-36f2-fcrx-fp4j