Debian update for libapache2-mod-auth-openidc

1) Input validation error

EUVDB-ID: #VU112073

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-3891

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input when OIDCPreservePost is enabled in mod_auth_openidc. A remote attacker can send an HTTP POST request without a Content-Type header and crash the web server. 

Mitigation

Update libapache2-mod-auth-openidc package to version 2.4.12.3-2+deb12u4.

Vulnerable software versions

Debian Linux: All versions

libapache2-mod-auth-openidc (Debian package): before 2.4.12.3-2+deb12u4

CPE2.3

• cpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
• cpe:2.3:a:debian:libapache2-mod-auth-openidc_debian_package:*:*:*:*:*:debian_linux:*:*

External links

https://lists.debian.org/debian-security-announce/2025/msg00080.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.