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.
Integer Overflow or Wraparound 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.