#VU79695 Format string error in mod_auth_openidc - CVE-2021-32785

Vulnerability identifier: #VU79695

Vulnerability 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-2021-32785

CWE-ID: CWE-134

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
mod_auth_openidc
Web applications / Modules and components for CMS

Vendor: ZmartZone IAM

Description

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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

mod_auth_openidc: before 2.4.9

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External links
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

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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.