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.

The mod_auth_shadow module 1.4 and earlier does not properly enforce the expiration of a user account and password, which could allow remote authenticated users to bypass intended access restrictions.