Vigil@nce - FreeBSD: denial of service via TCP MD5
March 2016 by Vigil@nce
This bulletin was written by Vigil@nce : https://vigilance.fr/offer
SYNTHESIS OF THE VULNERABILITY
A local (remote in some special configurations) attacker can send
a malicious TCP packet to FreeBSD, in order to trigger a denial of
service.
Impacted products: FreeBSD.
Severity: 2/4.
Creation date: 14/01/2016.
DESCRIPTION OF THE VULNERABILITY
The FreeBSD kernel (with option TCP_SIGNATURE) implements the RFC
2385, which uses a MD5 signature on TCP packets.
However, when both TCP_NOOPT and TCP_MD5SIG options are active on
a socket, a fatal error occurs.
A local (remote in some special configurations) attacker can
therefore send a malicious TCP packet to FreeBSD, in order to
trigger a denial of service.
ACCESS TO THE COMPLETE VIGIL@NCE BULLETIN
https://vigilance.fr/vulnerability/FreeBSD-denial-of-service-via-TCP-MD5-18726