Format string error in mod_auth_openidc - CVE-2021-32785

Vulnerability identifier: #VU79695

CSH Severity: Medium

CVSS v4: 8.7 [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]

CVE-ID: CVE-2021-32785

CWE-ID: CWE-134

Exploitation vector: Remote access

Exploit availability: No public exploit available

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

The vulnerability exists due to a format string error as mod_auth_openidc wrongly performs argument interpolation before passing Redis requests to `hiredis. A remote attacker can supply a specially crafted input that contains format string specifiers and perform a denial of service (DoS) attack.

mod_auth_openidc
SUSE Linux Enterprise Server
SUSE Linux Enterprise Module for Server Applications
apache2-mod_auth_openidc
apache2-mod_auth_openidc-debuginfo
apache2-mod_auth_openidc-debugsource
IBM Cloud Pak for Business Automation

Install updates from vendor's website.

mod_auth_openidc - update to 2.4.9
apache2-mod_auth_openidc - addressed in versions 2.3.8-3.15.1, 2.4.0-3.23.1
apache2-mod_auth_openidc-debuginfo - addressed in versions 2.3.8-3.15.1, 2.4.0-3.23.1
apache2-mod_auth_openidc-debugsource - addressed in versions 2.3.8-3.15.1, 2.4.0-3.23.1
IBM Cloud Pak for Business Automation - addressed in versions 21.0.3-IF037, 24.0.0-IF003

• https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-55r8-6w97-xxr4
• https://github.com/zmartzone/mod_auth_openidc/commit/dc672688dc1f2db7df8ad4abebc367116017a449
• https://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9
• https://security.netapp.com/advisory/ntap-20210902-0001/
• https://www.oracle.com/security-alerts/cpuapr2022.html
• https://lists.debian.org/debian-lts-announce/2023/04/msg00034.html

• Multiple vulnerabilities in mod_auth_openidc
• SUSE update for apache2-mod_auth_openidc
• SUSE update for apache2-mod_auth_openidc
• Multiple vulnerabilities in IBM Cloud Pak for Business Automation