A vulnerability was found in mod_auth_mellon before v0.14.2. An open redirect in the logout URL allows requests with backslashes to pass through by assuming that it is a relative URL, while the browsers silently convert backslash characters into forward slashes treating them as an absolute URL. This mismatch allows an attacker to bypass the redirect URL validation logic in apr_uri_parse function.
The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.
| Link | Tags |
|---|---|
| https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3877 | issue tracking third party advisory patch |
| https://github.com/Uninett/mod_auth_mellon/issues/35 | third party advisory patch |
| https://github.com/Uninett/mod_auth_mellon/commit/62041428a32de402e0be6ba45fe12df6a83bedb8 | third party advisory patch |
| https://usn.ubuntu.com/3924-1/ | third party advisory vendor advisory |
| https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CNW5YMC5TLWVWNJEY6AIWNSNPRAMWPQJ/ | vendor advisory |
| https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X7NLAU7KROWNTHAYSA2S67X347F42L2I/ | vendor advisory |
| https://access.redhat.com/errata/RHSA-2019:0766 | vendor advisory |
| https://access.redhat.com/errata/RHSA-2019:3421 | vendor advisory |