On Fri, 10 Jan 2003 11:05:01 -0000, "Greg Bolshaw" <greg@optionsinternet.com> wrote: >Product: Efficient Networks 5861 DSL Router > http://www.efficient.com/ebz/5800.html >Tested version: 5.3.80 (Latest firmware) >Advisory date: 10/01/2003 >Severity: Moderate > >Background > [...] > >As far as I am aware, the 5861 is the standard router provided to all ADSL >business customers in the UK. >From which provider? > >Details > >When using the builtin IP filtering to block incoming TCP SYN flags, a >simple portscan to the WAN interface of the router will cause the it to lock >up, and eventually restart. I have confirmed this using the Sygate port scanner found at http://scan.sygate.com. [...] >Solution > >There is currently no fix for this exploit. I have contacted Efficient >Networks to inform them of the problem. A workarround is to disable the filtering on the router and make sure all unsolicited packets are forwarded to a machine with a capable firewall installed. This is what I am doing in one instance. Andrew. -- Andrew Hodgson, Bromyard, Herefordshire, UK. Email: Andrew@hodgsonfamily.org
