Secunia Security Advisory – David Herselman has reported a security issue in the mod_auth_shadow module for Apache, which potentially can be exploited by malicious people to bypass certain security restrictions.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/40418/sa17060.txt
Source: https://packetstormsecurity.com/files/40418/Secunia-Security-Advisory-17060.html