Heap-based buffer underflow in the readPostBody function in cgiutil.c in mapserv in MapServer 4.x before 4.10.4 and 5.x before 5.2.2 allows remote attackers to have an unknown impact via a negative value in the Content-Length HTTP header.

More... (http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2009-0840)