SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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.

MEDIUM 5.9EPSS 1.50%

Does this matter?

Lower severity and a low EPSS score (1.50%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1
5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
1.50% probability · 74th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-323, CWE-330
Affected
openidc/mod auth openidc · fedoraproject/fedora
Source
security-advisories@github.com
EPSS trend
0%3%5%26 October 2026: 1.50%26 October 202626 October 2026

EPSS 1.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.