CVE-2021-29456 json
Authelia allows open redirects on the logout endpoint
published 5y ago modified 4mo ago also GHSA-36f2-fcrx-fp4j , EUVD-2023-0845
- cvss
- 5.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 43%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- go github.com/authelia/authelia/v4 4.28.0
- authelia authelia 4.28.0
Is CVE-2021-29456 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N |
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 4.9 | AV:N/AC:M/Au:S/C:P/I:P/A:N |
| GitHub | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/authelia/authelia/v4 | <4.28.0 |
4.28.0 |
Affected products
- authelia authelia
Classification
- Weakness
-
- CWE-601 URL Redirection to Untrusted Site
References
-
github.com
/authelia/authelia/security/advisories/GHSA-36f2-fcrx-fp4j
web, patch, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-29456
advisory
-
github.com
/authelia/authelia
package
Sources
- CVE List CVE-2021-29456
- GitHub Advisory GHSA-36f2-fcrx-fp4j
- NVD CVE-2021-29456
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.