INFO: ====================================================== object class Failure to Handle Exceptional Conditions remote Yes local No vulnerable: 3Com® HomeConnect® Cable Modem External with USB (#3CR29223 -- DISCONTINUED) Not Tested: (#3CR29223-A -- DISCONTINUED) DISCUSSION: ====================================================== HomeConnect is and External Cable modem manufactured by 3Com, and distributed by numerous Cable providers. A problem has been discovered in the cablemodem firmware that could make it possible for remote users to deny service to legitimate users of this network hardware. This hardware has port 80/TCP wide open for the entire network, letting any user on the internet to access the homepage that it has in it by default. The problem occurs when a user reaches this page, and making a request of a file (Existing or not) of more than 100 Characters. This will cause the modem to Reset in the best case. EXPLOIT: ======================================================= http://target3comcablemodem/<AAAAAAAAAAAAAAAAAAAA+100CHARS> (That is 100 characters) SOLUTION: ======================================================== As a workaround for this issue, users can filter port 80 of the Cablemodem Or else, since this modem is discontinued (they no longer make it) you should just call your ISP, tell them about the problem and ask to replace the cablemodem for a newer one. Alex S. Harasic aharasic@terra.cl
