Exploiting (?) lv2
September 19, 2012
A long while ago KaKaRoTo pointed me to a stack overflow he found while reversing lv2_kernel. But there are two problems:
- The vulnerability is in a protected syscall (the SELF calling it got to have the 0x40… control flags set). So you’d first need to find a suitable usermode exploit (don’t ask us), that gives you code execution with the right privileges.
- The payload data is copied to lv2 heap first and the function will do a free call on it before the payload has any chance to get executed. This might not sound like a problem but it looks like lv2’s heap implementation will overwrite the free’ed space with 0xABADCAFE and thus destroy the payload.
Here is my sample implementation for 3.41 lv2_kernel (although the vulnerability should be present in all versions of lv2 up to the latest firmware), maybe someone of you will find a way to overcome problem (2.) and can get something nice out of it because right now it’s only good to crash lv2.