CVE-2021-32791: fedoraproject fedora Reusing a Nonce, Key Pair in Encryption

Vulnerability summary

CVE-2021-32791 is a medium (CVSS 5.9) Reusing a Nonce, Key Pair in Encryption vulnerability in fedoraproject fedora. EPSS estimates a 1.50% chance of exploitation in the next 30 days, higher than 73.9% of scored vulnerabilities.

Timeline

1. 26-07-2021
   PublishedVulnerability first disclosed.
2. 03-08-2024
   Last modifiedVulnerability information updated.

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.

• CWE-323Reusing a Nonce, Key Pair in EncryptionNonces should be used for the present occasion and only once.
• CWE-330Use of Insufficiently Random ValuesThe product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.