[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Security flaw in iptables



Firstly, I wonder if people are aware of this?

"If an attacker can establish an FTP connection passing through a Linux
2.4.x IPTables firewall with the state options allowing 'related'
connections (almost 100% do), he can insert entries into the firewall's
RELATED ruleset table allowing the FTP Server to connect to any host and
port protected by the firewalls rules, including the firewall
itself...."

Check out this link:
http://www.tempest.com.br/advisories/01-2001.html

Secondly, what is the best way to circumvent this flaw?

Does the 2.4.3 kernel fix it; because I noted that there were a couple
of new modules in it for iptables?

Thirdly, If I don't have an ftp server on my computer then does that
mean that it won't affect me?  Assuming that all users on my side of the
firewall are totally trusted.

Thanks.

Mark.



Reply to: