FreeBSD -- TCP reassembly vulnerability
FreeBSD may add a reassemble queue entry on the stack
into the segment list when the reassembly queue reaches its
limit. The memory from the stack is undefined after the
function returns. Subsequent iterations of the reassembly
function will attempt to access this entry.
An attacker who can send a series of specifically crafted
packets with a connection could cause a denial of service
situation by causing the kernel to crash.
Additionally, because the undefined on stack memory may
be overwritten by other kernel threads, while extremely
difficult, it may be possible for an attacker to construct
a carefully crafted attack to obtain portion of kernel
memory via a connected socket. This may result in the
disclosure of sensitive information such as login credentials,
etc. before or even without crashing the system.
Copyright © 2003-2005 Jacques Vidrine and contributors.
Please see the source of this document for full copyright