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Smack the Stack - Advanced Buffer Overflow Methods (Virtual Address)
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SUMMARY
From time to time, a new patch or security feature is integrated to raise
the bar on buffer overflow exploiting. The paper linked here includes five
creative methods to overcome various stack protection patches, but in
practice focus on the VA (Virtual Address) space randomization patch that
have been integrated to Linux 2.6 kernel. These methods are not limited to
this patch or another, but rather provide a different approach to the
buffer overflow exploiting scheme.
DETAILS
VA Patch:
Causes certain parts of a process virtual address space to be different
for each invocation of the process. The purpose of this is to raise the
bar on buffer overflow exploits. As full randomization makes it not
possible to use absolute addresses in the exploit. Randomizing the stack
pointer and mmap() addresses. Which also effects where shared libraries
goes, among other things. The stack is randomized within an 8Mb range and
applies to ELF binaries. The patch intedned to be an addition to the NX
support that was added to the 2.6 kernel earlier as well. This paper
however addressed it as solo.
The full paper can be downloaded from:
<http://www.tty64.org/doc/smackthestack.txt>
http://www.tty64.org/doc/smackthestack.txt
ADDITIONAL INFORMATION
The information has been provided by <mailto:izik@tty64.org> Izik.
The original article can be found at:
<http://www.tty64.org/doc/smackthestack.txt>
http://www.tty64.org/doc/smackthestack.txt
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