Vulnerability Details : CVE-2021-39191
mod_auth_openidc is an authentication/authorization module for the Apache 2.x HTTP server that functions as an OpenID Connect Relying Party, authenticating users against an OpenID Connect Provider. In versions prior to 2.4.9.4, the 3rd-party init SSO functionality of mod_auth_openidc was reported to be vulnerable to an open redirect attack by supplying a crafted URL in the `target_link_uri` parameter. A patch in version 2.4.9.4 made it so that the `OIDCRedirectURLsAllowed` setting must be applied to the `target_link_uri` parameter. There are no known workarounds aside from upgrading to a patched version.
Vulnerability category: Open redirect
Products affected by CVE-2021-39191
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*
- cpe:2.3:a:openidc:mod_auth_openidc:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-39191
0.23%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 61 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-39191
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
5.8
|
MEDIUM | AV:N/AC:M/Au:N/C:P/I:P/A:N |
8.6
|
4.9
|
NIST | |
|
6.1
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
2.8
|
2.7
|
NIST | |
|
4.7
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N |
2.8
|
1.4
|
GitHub, Inc. |
CWE ids for CVE-2021-39191
-
A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks.Assigned by:
- nvd@nist.gov (Secondary)
- security-advisories@github.com (Primary)
References for CVE-2021-39191
-
https://github.com/zmartzone/mod_auth_openidc/issues/672
open redirect for target_link_uri parameter · Issue #672 · zmartzone/mod_auth_openidc · GitHubExploit
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https://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9.4
Release release 2.4.9.4 · zmartzone/mod_auth_openidc · GitHubRelease Notes
-
https://github.com/zmartzone/mod_auth_openidc/commit/03e6bfb446f4e3f27c003d30d6a433e5dd8e2b3d
apply OIDCRedirectURLsAllowed setting to target_link_uri · zmartzone/mod_auth_openidc@03e6bfb · GitHubPatch;Third Party Advisory
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https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RHXO4O4G2UQS7X6OQJCVZKHZAQ7SAIFB/
[SECURITY] Fedora 36 Update: mod_auth_openidc-2.4.9.4-1.fc36 - package-announce - Fedora Mailing-ListsMailing List
-
https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-2pgf-8h6h-gqg2
URL Redirection to Untrusted Site ('Open Redirect') in mod_auth_openidc · Advisory · zmartzone/mod_auth_openidc · GitHubVendor Advisory
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https://lists.debian.org/debian-lts-announce/2023/07/msg00020.html
[SECURITY] [DLA 3499-1] libapache2-mod-auth-openidc security updateMailing List
-
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/32RGPW5LZDLDTB7MKZIGAHPSLFOUNWR5/
[SECURITY] Fedora 35 Update: mod_auth_openidc-2.4.9.4-1.fc35 - package-announce - Fedora Mailing-ListsMailing List
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