SquidGuard versions 1.3 and 1.4 suffer from multiple buffer overflow vulnerabilities that can lead to filtering policy bypass and denial of service.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/82216/squidguard-overflow.txt
Source: https://packetstormsecurity.com/files/82216/SquidGuard-1.3-1.4-Buffer-Overflows.html