Cisco Systems
is urging network administrators to update their router firmware to
secure themselves against a set of two vulnerabilities in its IOS
software.
Cisco
said that the vulnerabilities lie in more than 26 variants of
12.3 and 12.4 versions of the ISO router operating system. The
company has issued a patch for both vulnerabilities, which affect
the Intrusion Prevention System (IPS) security component of the
software. By default, IPS is disabled in systems and must be
manually enabled.
If exploited, one of the vulnerabilities could be used to allow an
unauthorized user to bypass the security software. Attackers could
use the second flaw to launch a denial of service attack that will
result in a router to crash.
"Both flaws pose serious risks to vulnerable Cisco administrators.
You definitely don't want attackers knocking your gateway router
out for any amount of time," said network security analyst Cory
Nachreiner with Watchguard.
"Moreover, if you use Cisco's IPS you certainly don't want an
attacker to be able to evade it."
Cisco routers run about three quarters of the world's networks, but
Nachreiner quelled concerns by pointing out that the affected
component is disabled in most systems.
"If you do use one of the vulnerable versions of IOS listed in the
" Vulnerable Products" section of Cisco's alert, and you have
enabled IPS, then get to patching, my friend. Otherwise, no big
deal."