CVE-2021-32637

CRITICAL
Published May 28, 20215y ago · Modified Jun 17, 20262w ago
10.0 CVSS 3.1
Critical
Find Similar
Published May 28, 2021 5y ago
Last Modified Jun 17, 2026 2w ago

Description

Authelia is a a single sign-on multi-factor portal for web apps. This affects uses who are using nginx ngx_http_auth_request_module with Authelia, it allows a malicious individual who crafts a malformed HTTP request to bypass the authentication mechanism. It additionally could theoretically affect other proxy servers, but all of the ones we officially support except nginx do not allow malformed URI paths. The problem is rectified entirely in v4.29.3. As this patch is relatively straightforward we can back port this to any version upon request. Alternatively we are supplying a git patch to 4.25.1 which should be relatively straightforward to apply to any version, the git patches for specific versions can be found in the references. The most relevant workaround is upgrading. You can also add a block which fails requests that contains a malformed URI in the internal location block.

CVSS Details

Base Score
10.0
Exploitability
3.9
Impact
6.0
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Changed
Confidentiality High
Integrity High
Availability High

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-287 Improper Authentication Authentication

Affected Products 2

VendorProductVersionRange
autheliaauthelia*≥4.0.0  –  <4.25.1
autheliaauthelia*≥4.26.0  –  <4.29.3

References 2

  • github.com https://github.com/authelia/authelia/commit/c62dbd43d6e69ae81530e7c4f8763857f8ff1dda
    PatchThird Party Advisory
  • github.com https://github.com/authelia/authelia/security/advisories/GHSA-68wm-pfjf-wqp6
    ExploitMitigationPatchThird Party Advisory

Remediation

  • github.com https://github.com/authelia/authelia/commit/c62dbd43d6e69ae81530e7c4f8763857f8ff1dda
    PatchThird Party Advisory
  • github.com https://github.com/authelia/authelia/security/advisories/GHSA-68wm-pfjf-wqp6
    ExploitMitigationPatchThird Party Advisory