CVE-2021-39191
libapache2-mod-auth-openidc - security update
Description
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.
How to fix CVE-2021-39191
To remediate CVE-2021-39191, upgrade the affected package to a fixed version below.
- —upgrade to 2.4.9.4-0+deb11u1 or later
- —upgrade to 2.3.10.2-1+deb10u3 or later
Is CVE-2021-39191 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 2.4.9.4-0+deb11u1
- from 0, < 2.3.10.2-1+deb10u3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |