5.7

CVE-2021-29456: authelia Open Redirect

CVSS: 5.7v3.1MediumModified
AliasesGHSA-36f2-fcrx-fp4j
Published 21-04-2021Last modified 03-08-2024
Open JSON

Vulnerability summary

CVE-2021-29456 is a medium (CVSS 5.7) Open Redirect vulnerability in authelia. EPSS estimates a 0.51% chance of exploitation in the next 30 days, higher than 42.2% of scored vulnerabilities.

Overall risk
23/100
0100
Low · default modelHow is this calculated?
CVSS score
5.7/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.51%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 21-04-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

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 metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.51%

Chance of exploitation in the next 30 days

Percentile

42%

Versus all other CVEs

30-day change

0.00 pp

From 0.51% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.51%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Authelia1 product
Github.com/authelia/authelia1 product
  • v4< 4.28.0

2 vendors · 2 products

References

3 links