PowerCHM suffers from a stack-based buffer overflow when processing files with the .HHP extension. Version 5.7 is affected.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/76084/Bkis-05-2009.txt
Source: https://packetstormsecurity.com/files/76084/PowerCHM-Stack-Based-Buffer-Overflow.html