HOMEVULNERABILITIESCVE-2021-32791
MEDIUM

CVE-2021-32791

CWE-323Published: July 26, 2021· Updated: Jun 17, 2026

5.9
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-32791 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 5.9.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityHigh
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected Vendors & Products

Apache1 product(s)
http server
Fedora1 product(s)
fedora
openidc1 product(s)
mod auth openidc
Source: NVD CPE · 4 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/zmartzone/mod_auth_openidc/commit/375407c16c61a70b56fdbe13b0d2c8f11398e92c
PATCHhttps://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-px3c-6x7j-3r9r
PATCHhttps://www.oracle.com/security-alerts/cpuapr2022.html
PATCHhttps://github.com/zmartzone/mod_auth_openidc/commit/375407c16c61a70b56fdbe13b0d2c8f11398e92c
PATCHhttps://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-px3c-6x7j-3r9r
PATCHhttps://www.oracle.com/security-alerts/cpuapr2022.html
ADVISORYhttps://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9
ADVISORYhttps://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9

All References (14)

→
https://github.com/zmartzone/mod_auth_openidc/commit/375407c16c61a70b56fdbe13b0d2c8f11398e92cPatch · Third Party Advisory
→
https://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9Release Notes · Third Party Advisory
→
https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-px3c-6x7j-3r9rPatch · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2023/04/msg00034.html
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FZVF6BSJLRQZ7PFFR4X5JSU6KUJYNOCU/
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QXAWKPT5LXZSUTFSJ6IWSZC7RMYYQXQD/
→
https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch · Third Party Advisory
→
https://github.com/zmartzone/mod_auth_openidc/commit/375407c16c61a70b56fdbe13b0d2c8f11398e92cPatch · Third Party Advisory
→
https://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9Release Notes · Third Party Advisory
→
https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-px3c-6x7j-3r9rPatch · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2023/04/msg00034.html
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FZVF6BSJLRQZ7PFFR4X5JSU6KUJYNOCU/
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QXAWKPT5LXZSUTFSJ6IWSZC7RMYYQXQD/
→
https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch · Third Party Advisory

Quick Facts

CVE IDCVE-2021-32791
CVSS Score5.9 / 10
SeverityMEDIUM
WeaknessCWE-323
CISA KEVNo
Affected3 vendor(s)
PublishedJul 26, 2021

Related CVEs (CWE-323)

CVE-2017-7902
9.8
CVE-2026-12205
9.1
CVE-2026-49952
9.1
CVE-2025-64767
9.1
CVE-2026-59099
9.1
CVE-2022-24401
8.1

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-32791 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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