Vigil@nce - NetBSD: denial of service via kqueue
March 2013 by Vigil@nce
This bulletin was written by Vigil@nce : http://vigilance.fr/offer
SYNTHESIS OF THE VULNERABILITY
A local attacker can use the kqueue() and kevent() functions on a malicious file descriptor, in order to stop the system.
Impacted products: NetBSD
Creation date: 27/02/2013
DESCRIPTION OF THE VULNERABILITY
The kqueue() system call requests the kernel to inform the process when some events occur. The kevent() function is used to alter the list of events to track, and returns the last events.
When the kqueue() function is called on a file descriptor which does not support to be monitored, the fnullop_kqfilter() function does not detect the error. The next call to kevent() then dereferences a NULL function pointer.
A local attacker can therefore use the kqueue() and kevent() functions on a malicious file descriptor, in order to stop the system.
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