Security readout for executives and security teams
Plain-English summary
This flaw could let an unauthenticated attacker bypass Authelia protection when Authelia is used with nginx auth_request and a malformed request URI reaches the authentication flow. If exposed, protected applications may be reachable without the intended single sign-on and MFA controls.
Executive priority
Treat this as an immediate remediation item for affected nginx and Authelia deployments, especially where Authelia protects administrative, customer, or production applications. The business risk is loss of access-control enforcement, not just a service defect.
Technical view
CVE-2021-32637 is a CWE-287 authentication bypass in Authelia versions >= 4.0.0-alpha1 and < 4.29.3. The confirmed scenario is nginx ngx_http_auth_request_module with Authelia, where malformed URI handling can bypass authentication. CVSS 3.1 is 10.0 with network, unauthenticated attack conditions.
Likely exposure
Highest exposure is Authelia deployments before 4.29.3 fronting applications through nginx auth_request. The advisory says other proxies are only theoretical, and officially supported proxies except nginx do not allow malformed URI paths.
Exploitation context
The provided bundle does not establish active exploitation, and KEV is false. The issue is still urgent because it is unauthenticated, network reachable, and can bypass SSO/MFA for protected applications in the confirmed nginx configuration.
Researcher notes
Evidence is strongest for nginx auth_request integrations. The source bundle names the fixed release, affected version range, workaround direction, and upstream commit, but does not provide evidence of exploitation in the wild or confirmed impact on non-nginx proxies.
Mitigation direction
- Upgrade Authelia to v4.29.3 or later.
- Apply the vendor-provided patch or request an appropriate backport if upgrade is blocked.
- Add nginx handling that rejects malformed URI requests in the internal location block.
- Review vendor guidance before changing unsupported proxy configurations.
Validation and detection
- Inventory Authelia versions and flag anything below 4.29.3.
- Identify deployments using nginx ngx_http_auth_request_module with Authelia.
- Verify the fixed version or vendor patch is present.
- Confirm malformed-URI requests are rejected in a safe staging test.
- Review logs for authentication bypass indicators without relying on log evidence alone.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-287: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-32637 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 10 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H3.96Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
10CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/authelia/authelia/security/advisories/GHSA-68wm-pfjf-wqp6CVE reference · x_refsource_CONFIRM
- https://github.com/authelia/authelia/commit/c62dbd43d6e69ae81530e7c4f8763857f8ff1ddaCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.