The siteaccess URIMatching implementation in eZ publish 3.5 through 3.8 before 20050812 converts all non-alphanumeric characters in a URI to '_' (underscore), which allows remote attackers to bypass access restrictions by inserting certain characters in a URI, as demonstrated by a request for /admin:de, which matches a rule allowing only /admin_de to access /admin.
CWE-264