CVE-2021-32791
CVE-2021-32791 — Hardcoded static IV and AAD with a reused key in AES GCM encryption in mod_auth_openidc
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 mod_auth_openidc before version 2.4.9, the AES GCM encryption in mod_auth_openidc uses a static IV and AAD. It is important to fix because this creates a static nonce and since aes-gcm is a stream cipher, this can lead to known cryptographic issues, since the same key is being reused. From 2.4.9 onwards this has been patched to use dynamic values through usage of cjose AES encryption routines.
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
2%
chance of exploitation in 30 days
CVSS base
5.9
MEDIUM
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 5.9 | CVSS 3.1 | MEDIUM | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-323
- CWE-330
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
- T1110Brute Force
- T1552.004Unsecure Credentials: Private Keys
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /authorization.
References
7 on the record
- github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9
reference
- github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-px3c-6x7j-3r9r
reference
- github.com/zmartzone/mod_auth_openidc/commit/375407c16c61a70b56fdbe13b0d2c8f11398e92c
reference
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FZVF6BSJLRQZ7PFFR4X5JSU6KUJYNOCU/
vendor-advisory
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QXAWKPT5LXZSUTFSJ6IWSZC7RMYYQXQD/
vendor-advisory
- www.oracle.com/security-alerts/cpuapr2022.html
reference
- lists.debian.org/debian-lts-announce/2023/04/msg00034.html
mailing-list
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.