CVE-2021-32785 Detail

Current 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.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  7.5 HIGH
Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
Base Score:  5.3 MEDIUM
Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: It is possible that the NVD CVSS may not match that of the CNA. The most common reason for this is that publicly available information does not provide sufficient detail or that information simply was not available at the time the CVSS vector string was assigned.

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Hyperlink Resource
https://github.com/zmartzone/mod_auth_openidc/commit/dc672688dc1f2db7df8ad4abebc367116017a449 Patch  Third Party Advisory 
https://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9 Release Notes  Third Party Advisory 
https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-55r8-6w97-xxr4 Mitigation  Third Party Advisory 
https://security.netapp.com/advisory/ntap-20210902-0001/

Weakness Enumeration

CWE-ID CWE Name Source
CWE-134 Use of Externally-Controlled Format String cwe source acceptance level NIST   Provider acceptance level GitHub, Inc.  

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Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-32785
NVD Published Date:
07/22/2021
NVD Last Modified:
09/02/2021
Source:
GitHub, Inc.