Remote denial of service in 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

Install updates from vendor's website.

Vulnerable software versions

mod_auth_openidc: 2.0.0 - 2.4.13.1

CPE2.3

• cpe:2.3:a:zmartzone:mod_auth_openidc:2.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:zmartzone:mod_auth_openidc:2.1.0:*:*:*:*:*:*:*
• cpe:2.3:a:zmartzone:mod_auth_openidc:2.1.1:*:*:*:*:*:*:*

External links

https://github.com/OpenIDC/mod_auth_openidc/security/advisories/GHSA-x7cf-8wgv-5j86
https://bugzilla.redhat.com/show_bug.cgi?id=2361633

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.