CVE-2021-32786
As a result, this function can be bypassed and leads to an Open Redirect vulnerability in the logout functionality.
Does this matter?
Lower severity and a low EPSS score (2.36%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 2.36% probability · 84th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-601
- Affected
- openidc/mod auth openidc · fedoraproject/fedora
- Source
- security-advisories@github.com
EPSS 2.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://daniel.haxx.se/blog/2017/01/30/one-url-standard-please/Exploit, Third Party Advisory
- https://github.com/zmartzone/mod_auth_openidc/commit/3a115484eb927bc6daa5737dd84f88ff4bbc5544Patch, 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-xm4c-5wm5-jqv7Third 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://security.netapp.com/advisory/ntap-20210902-0001/Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
- https://daniel.haxx.se/blog/2017/01/30/one-url-standard-please/Exploit, Third Party Advisory
- https://github.com/zmartzone/mod_auth_openidc/commit/3a115484eb927bc6daa5737dd84f88ff4bbc5544Patch, 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-xm4c-5wm5-jqv7Third 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://security.netapp.com/advisory/ntap-20210902-0001/Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.