CVE-2021-32786
Publication date 22 July 2021
Last updated 24 July 2024
Ubuntu priority
Cvss 3 Severity Score
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.
Status
Package | Ubuntu Release | Status |
---|---|---|
libapache2-mod-auth-openidc | 24.10 oracular |
Not affected
|
24.04 LTS noble |
Not affected
|
|
22.04 LTS jammy |
Not affected
|
|
20.04 LTS focal |
Not affected
|
|
18.04 LTS bionic |
Not affected
|
|
16.04 LTS xenial |
Vulnerable
|
|
14.04 LTS trusty | Not in release |
Severity score breakdown
Parameter | Value |
---|---|
Base score | 6.1 · Medium |
Attack vector | Network |
Attack complexity | Low |
Privileges required | None |
User interaction | Required |
Scope | Changed |
Confidentiality | Low |
Integrity impact | Low |
Availability impact | None |
Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
References
Other references
- https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-xm4c-5wm5-jqv7
- https://github.com/zmartzone/mod_auth_openidc/commit/3a115484eb927bc6daa5737dd84f88ff4bbc5544 (v2.4.9)
- https://daniel.haxx.se/blog/2017/01/30/one-url-standard-please/
- https://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9
- https://github.com/zmartzone/mod_auth_openidc/commit/3a115484eb927bc6daa5737dd84f88ff4bbc5544
- https://www.cve.org/CVERecord?id=CVE-2021-32786