Vulnerability in Apache Http Server
CVE-2021-32791
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.
EPSS: 0.015 (71.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Apache Http_server
- Openidc Mod_auth_openidc
- Zmartzone Mod_auth_openidc — versions < 2.4.9
- Fedoraproject Fedora — versions 33, 34
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (Third Party Advisory, Release Notes)
- security-advisories@github.com (Patch, Third Party Advisory)
- security-advisories@github.com (Patch, Third Party Advisory)
- security-advisories@github.com (vendor-advisory)
- security-advisories@github.com (vendor-advisory)
- security-advisories@github.com (Patch, Third Party Advisory)
- security-advisories@github.com (mailing-list)
Frequently asked questions
- What is CVE-2021-32791?
- CVE-2021-32791 is a medium-severity vulnerability in Apache Http Server, classified under Reusing a Nonce, Key Pair in Encryption. CVSS score: 5.9/10. Published 2021-07-26.
- How severe is CVE-2021-32791?
- Medium severity. CVSS v3 base score is 5.9 out of 10.
- Is CVE-2021-32791 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.