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.
Uninett mod_auth_mellon Module is prone to an open-redirection vulnerability. An attacker can leverage this issue by constructing a crafted URI and enticing a user to follow it. When an unsuspecting victim follows the link, they may be redirected to an attacker-controlled site; this may aid in phishing attacks or gain sensitive information. Other attacks are possible.
Updates are available. Please see the references or vendor advisory for more information.
Currently, we are not aware of any working exploits.