Mandriva Linux Security Advisory – The mod_auth_shadow module 1.0 through 1.5 and 2.0 for Apache with AuthShadow enabled uses shadow authentication for all locations that use the require group directive, even when other authentication mechanisms are specified, which might allow remote authenticated users to bypass security restrictions.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/41055/MDKSA-2005-200.txt
Source: https://packetstormsecurity.com/files/41055/Mandriva-Linux-Security-Advisory-2005.200.html