MS05-025 PNG Image Rendering Vulnerability2005-06-21

Spent some time with spoonm over the weekend at RECON tinkering with the MS05-025 PNG vulnerability. Using my own not-as-cool-as-halvar's bindiff tool I came across the following significant change:


The left column is pre-patch and the right column is post-patch. Further tracing reveals the actual vulnerable loop that leads to heap corruption, a jump table for which case 0x9 is required to reach the vulnerable function and some other interesting tidbits. All in all the vulnerability wasn't difficult to pin point, the biggest hurdle is overcoming the lazyness required to generate a valid PNG image as the CRC checks are done prior to reaching the vulnerable code.

OpenRCE Site Launch2005-06-20

Just got back from RECON in Montreal. The trip back was miserable (4 flights spanning over 12 hours due to cancellations etc.) but the con was great. Lots of great speakers including Nicolas Brulez, Andrew Griffiths and spoonm. My talk was well received, RECON was definetely the perfect venue for Process Stalker.

On another note. I finally unveiled my latest pet project, the Open Reverse Code Engineering community site, The site is very usable but has many features still under development. Please share any comments, suggestions, bug reports and especially content with one of the site admins.

Windows Heap Visualization2005-06-01

You may have noticed the ghosted 'Heap' option under the 'View' menu in OllyDBG. The feature is available only under Windows 95 based OSes and is supposed to display a list of allocated memory blocks. I've written a plug-in, Olly Heap Vis, to provide this missing functionality and more on all modern Windows OSes such as Windows 2000, XP and 2003.

The Olly Heap Vis plug-in provides heap chunk lists, the ability to search the heap, a quick heap jump and finally visualization capabilities through Graphviz. More information and source code is available in the bundled archive.