A denial-of-service vulnerability in one of the most popular cable and DSL routers allows an attacker to crash the router from a remote location.

The Linksys Group Inc.'s BEFSR41 EtherFast Cable/DSL Router with 4-Port Switch is vulnerable to a remote DoS attack that requires the attacker to do nothing more than access a specific script on the router's remote management interface. The vulnerability affects all of the routers with firmware versions earlier than 1.42.7.

There is no patch available for the problem at this point, but firmware version 1.43 fixes the problem.

In order to exploit the vulnerability, an attacker would simply need to access the Gozilla.cgi script using the router's IP address with no arguments. As long as the router's remote management interface is enabled, the attacker simply needs to craft a URL that looks like this—http://192.168.1.1/Gozilla.cgi?—and send it to the router, which would then crash, according to an advisory published Friday by iDefense Inc., a security firm based in Chantilly, Va.

fonte: eWeek