7.5
CVSSv3

CVE-2021-32785

Published: 22/07/2021 Updated: 30/01/2024
CVSS v2 Base Score: 4.3 | Impact Score: 2.9 | Exploitability Score: 8.6
CVSS v3 Base Score: 7.5 | Impact Score: 3.6 | Exploitability Score: 3.9
VMScore: 383
Vector: AV:N/AC:M/Au:N/C:N/I:N/A:P

Vulnerability Summary

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 before 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.

Vulnerability Trend

Vulnerable Product Search on Vulmon Subscribe to Product

openidc mod_auth_openidc

netapp cloud backup -

debian debian linux 10.0

Vendor Advisories

Debian Bug report logs - #991583 libapache2-mod-auth-openidc: CVE-2021-32785 Package: src:libapache2-mod-auth-openidc; Maintainer for src:libapache2-mod-auth-openidc is Moritz Schlarb <schlarbm@uni-mainzde>; Reported by: Salvatore Bonaccorso <carnil@debianorg> Date: Tue, 27 Jul 2021 20:09:06 UTC Severity: important ...