CVE-2021-32785
5.3 · MEDIUMOverview
CVE-2021-32785 is a medium-severity vulnerability affecting openidc mod_auth_openidc. It was published on July 22, 2021 and has a CVSS 3.1 base score of 5.3 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.3, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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
Remediation
Check the references section for vendor advisories and patches from openidc. Update mod_auth_openidc to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| openidc | mod_auth_openidc | >= 0, < 2.4.9 | Affected |
| apache | http_server | 2.0.0 | Affected |
References
Frequently Asked Questions
What is CVE-2021-32785?
CVE-2021-32785 is a medium-severity vulnerability affecting openidc mod_auth_openidc. It was published on July 22, 2021 and has a CVSS 3.1 base score of 5.3 (MEDIUM).
How severe is CVE-2021-32785?
This vulnerability has a CVSS 3.1 base score of 5.3, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-32785?
Check the references section for vendor advisories and patches from openidc. Update mod_auth_openidc to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-32785?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-32785 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
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