Integer overflow in the XPMReader::ReadXPM function in filter.vcl/ixpm/svt_xpmread.cxx in OpenOffice.org (OOo) before 3.2 allows remote attackers to execute arbitrary code via a crafted XPM file that triggers a heap-based buffer overflow.
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.