source: http://www.securityfocus.com/bid/3027/info

A wide range of products exists for scanning enterprise email and filesystems for files containing viruses and other undesirable content.

These products handle compressed files by temporarily unzipping them and scanning their uncompressed contents.

It is possible to construct an archive with an unusually high compression ratio, resulting in a small file which grows to extreme size when uncompressed.

When a scanner process unpacks such an archive to examine its contents, the resulting file may be so large that it consumes significant amounts of available disk space.

https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/bin-sploits/21006.zip