CVE-2021-32786 Open Redirect in oidc_validate_redirect_url()

What is CVE-2021-32786?

CVE-2021-32786 is a medium-severity vulnerability in Fedoraproject Fedora, published on 22 Jul 2021.

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 versions prior to 2.4.9, `oidc_validate_redirect_url()` does not parse URLs the same way as most browsers do. As a result, this function can be bypassed and leads to an Open Redirect vulnerability in the logout functionality. This bug has been fixed in version 2.4.9 by replacing any backslash of the URL to redirect with slashes to address a particular breaking change between the different specifications (RFC2396 / RFC3986 and WHATWG). As a workaround, this vulnerability can be mitigated by configuring `mod_auth_openidc` to only allow redirection whose destination matches a given regular expression.

Weakness: CWE-601

Which versions are affected by CVE-2021-32786?

It affects 2 products.

Products include Fedoraproject Fedora, Openidc Mod Auth Openidc.

How do I fix CVE-2021-32786?

Upgrade to a fixed version.

Is CVE-2021-32786 being exploited?

There is no known exploitation of CVE-2021-32786 in the wild and no public exploit code.

Other vulnerabilities in Fedoraproject Fedora

• CVE-2024-4577 PHP-CGI OS Command Injection Exploited Critical 9.8
• CVE-2021-39226 Grafana Authentication Bypass Exploited Critical 9.8
• CVE-2019-5544 VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow Exploited Critical 9.8
• CVE-2024-4947 Google Chromium V8 Type Confusion Exploited Critical 9.6
• CVE-2024-4671 Google Chromium Visuals Use-After-Free Exploited Critical 9.6

All Fedoraproject Fedora vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-6480, DEBIAN-CVE-2021-32786, GHSA-xm4c-5wm5-jqv7, UBUNTU-CVE-2021-32786.