Chrome 21 hit Windows a few days ago and I’ve been meaning to write a post letting users know that they should know be running the PPAPI Flash Plugin by default (check chrome://plugins), which enables a far more restrictive sandbox.
How much stronger is this sandbox? IBM has written a wonderful whitepaper about it comparing the Firefox NPAPI Flash Sandbox, Chrome NPAPI Flash Sandbox, and the newly rolled out Chrome PPAPI Flash Sandbox.
The PPAPI Sandbox adds a number of restrictions. Here’s a few screenshots of the presentation that highlight some important areas.
As you can see the Pepper Flash is significantly more secure than the NPAPI Plugin used previously and currently. It has considerably reduced read access, write access, and registry access as well as stronger and more restrictive job tokens.
The first sandbox bypass for Chrome by Vupen used the Flash plugin because the sandbox for it was the weak link. Firefox’s sandbox has improved somewhat over the old Chrome sandbox but the latest iteration, Pepper, is much stronger than either of the two.
Flash exploits in the wild are going to drop significantly, just as they did with Adobe reader.