Date: Fri, 23 Jan 2009 13:42:03 -0800
Subject: Problems with syscall filtering technologies on Linux
From: Chris Evans <scarybeasts@gmail.com.>
To: [email protected], [email protected]
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Hi,
There's a trick which may permit the bypassing of policies in
technologies which do syscall filtering on the Linux x86_64 kernel.
The trick is made possible by the fact that the 32-bit and 64-bit
kernel tables are different, combined with the fact that a 64-bit
process can make a 32-bit syscall and visa versa. The syscall "number"
check can get confused and permit a syscall it did not intend to.
Advisory: http://scary.beasts.org/security/CESA-2009-001.html
Blog post: http://scarybeastsecurity.blogspot.com/2009/01/bypassing-syscall-filtering.html
Cheers
Chris
