http://www.eweek.com/article2/0,3959,663801,00.asp By Dennis Fisher November 1, 2002 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 firmaware 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. "Exploitation may be particularly dangerous, especially if the router's remote management capability is enabled," the advisory said. "An attacker can trivially crash the router by directing the URL…to its external interface." In many cases, there is no reason for the remote management interface to be enabled and disabling it serves as an easy defense against this problem. Linksys routers are used by many home workers to split broadband connections among several computers. A message on a security mailing list Friday from Mark Litchfield of Next Generation Security Software Ltd. suggested that routers and wireless access points from D-Link Systems Inc., and Linksys access points are also vulnerable to a DoS condition. - ISN is currently hosted by Attrition.org To unsubscribe email majordomoat_private with 'unsubscribe isn' in the BODY of the mail.
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