CVE-2021-32785 Information

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. When mod_auth_openidc versions prior to 2.4.9 are configured to use an unencrypted Redis cache (OIDCCacheEncrypt off OIDCSessionType server-cache OIDCCacheType redis) mod_auth_openidc wrongly performed argument interpolation before passing Redis requests to hiredis which would perform it again and lead to an uncontrolled format string bug. Initial assessment shows that this bug does not appear to allow gaining arbitrary code execution but can reliably provoke a denial of service by repeatedly crashing the Apache workers. This bug has been corrected in version 2.4.9 by performing argument interpolation only once using the hiredis API. As a workaround this vulnerability can be mitigated by setting OIDCCacheEncrypt to on as cache keys are cryptographically hashed before use when this option is enabled.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Reference

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

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

7.5