Secunia Security Advisory - A vulnerability has been reported in OpenBSD, which can be exploited by malicious, local users to cause a DoS (Denial of Service). The vulnerability is caused due to an error in the TCP stack when calculating TCP retransmission timeouts. This can be exploited to crash the system by sending some specially crafted packets with specific values in the TCP timestamp option.
01dfe21b277aa6a3cabb668c46629de39e0a77f728da1dfa5a2923c9dc64db09
TITLE:
OpenBSD TCP Retransmission Timeout Calculation Denial of Service
SECUNIA ADVISORY ID:
SA13819
VERIFY ADVISORY:
http://secunia.com/advisories/13819/
CRITICAL:
Not critical
IMPACT:
DoS
WHERE:
Local system
OPERATING SYSTEM:
OpenBSD 3.x
http://secunia.com/product/100/
DESCRIPTION:
A vulnerability has been reported in OpenBSD, which can be exploited
by malicious, local users to cause a DoS (Denial of Service).
The vulnerability is caused due to an error in the TCP stack when
calculating TCP retransmission timeouts. This can be exploited to
crash the system by sending some specially crafted packets with
specific values in the TCP timestamp option.
SOLUTION:
Apply patches.
OpenBSD 3.6:
ftp://ftp.openbsd.org/pub/OpenBSD/patches/3.6/common/010_rtt.patch
OpenBSD 3.5:
ftp://ftp.openbsd.org/pub/OpenBSD/patches/3.5/common/027_rtt.patch
PROVIDED AND/OR DISCOVERED BY:
Reported by vendor.
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