> try yourself with OpenOffice.org 2.1: > http://www.milw0rm.com/sploits/12122006-djtest.doc This looks like it's an integer overflow that's then crashing on when memset tries to write lots of zeros onto the heap. Breakpoint 2, WW8PLCF::GeneratePLCF (this=0xb12a36e8, pSt=0xabae6cc8, nPN=0, ncpN=587202560) at /usr/src/debug/OOD680_m5/sw/source/filter/ww8/ww8scan.cxx:2299 2299 nIMax = ncpN; Current language: auto; currently c++ (gdb) list 2294 2295 void WW8PLCF::GeneratePLCF( SvStream* pSt, long nPN, long ncpN ) 2296 { 2297 ASSERT(!this, "Not a bug, but I (cmc) want to see this .doc as an example"); 2298 ASSERT( nIMax < (long)ncpN, "Pcl.Fkp: Warum ist PLCF zu gross ?" ); 2299 nIMax = ncpN; 2300 long nSiz = 6 * nIMax + 4; 2301 pPLCF_PosArray = new INT32[ ( nSiz + 3 ) / 4 ]; // Pointer auf Pos-Array 2302 memset( pPLCF_PosArray, 0, (size_t)nSiz ); (gdb) print ncpN $1 = 587202560 (gdb) print nSiz $2 = -771751932 (gdb) print *pPLCF_PosArray $3 = 0 The memset at line 2302 tries to write 3523215364 zeros onto the heap at the location of pPLCF_PosArray. I don't see this exploitable beyond a DoS given the codepath here. If someone else could take a look and agree or disagree with me I would appreciate it. -- JB
