Vulnerability Details : CVE-2021-32637
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.
Vulnerability category: BypassGain privilege
Products affected by CVE-2021-32637
- cpe:2.3:a:authelia:authelia:*:*:*:*:*:*:*:*
- cpe:2.3:a:authelia:authelia:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-32637
0.39%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 74 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-32637
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
7.5
|
HIGH | AV:N/AC:L/Au:N/C:P/I:P/A:P |
10.0
|
6.4
|
NIST | |
10.0
|
CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
3.9
|
6.0
|
NIST | |
10.0
|
CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
3.9
|
6.0
|
GitHub, Inc. |
CWE ids for CVE-2021-32637
-
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.Assigned by: security-advisories@github.com (Primary)
References for CVE-2021-32637
-
https://github.com/authelia/authelia/commit/c62dbd43d6e69ae81530e7c4f8763857f8ff1dda
fix(handlers): align response status codes for the verify endpoint (#… · authelia/authelia@c62dbd4 · GitHubPatch;Third Party Advisory
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https://github.com/authelia/authelia/security/advisories/GHSA-68wm-pfjf-wqp6
Authentication bypassed with malformed request URI on nginx · Advisory · authelia/authelia · GitHubExploit;Mitigation;Patch;Third Party Advisory
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