Dear Gregory Duchemin, In case of the product like ADSL modem is, it's not a bug, but a leak of feature to secure DHCP and/or dynamic DNS updates, because it's a way DHCP and DNS are supposed to work and it's impossible to fix it without implementing protocol extensions. This products are targeted for SOHO (any corporate user already have DNS/DHCP server implemented) where this kind of attack does not lead to any serious threats. --Friday, November 12, 2004, 9:02:28 AM, you wrote to bugtraq@xxxxxxxxxxxxxxxxx: GD> Upon complete DHCP negociation, Alcatel modem will try to register the GD> client's DHCP HOSTNAME option into its local DNS domain. GD> At this point, it will care about the hostname syntax and will also GD> check it for redundancy. GD> It will simply discard any DNS dynamic update if the proposed hostname GD> already exists. GD> If it doesn't, an entry is added to the end of the local zone file. GD> However any new DHCP request for an already existing lease, including GD> a redundant HOSTNAME, will bypass this checking. GD> We have now two entries with the same hostname but two differents ip GD> addresses. -- ~/ZARAZA Ïîÿâèëñÿ íîâûé òèï ýëåìåíòàðíûõ ÷àñòèö - øêâàðêè. Íå î÷åíü áîëüøèå, ñëåãêà ïîäãîðåâøèå. (Ëåì)
