Firewall Wizards mailing list archives
SSH can be semi DOS'ed
From: "R. DuFresne" <dufresne () sysinfo com>
Date: Wed, 23 Dec 1998 16:27:24 -0600 (CST)
Folks, Seems at least older versions of ssh <ssh-1.2.17> can be somewhat DOS'ed, at least when not compiled with libwrap.a supporyt when the system is locked down with tcpd to all but a few allowed hosts. The Key is for the attacker to telnet to the ssh port, enter a few returns or something, then close the telnet connections. This leaves the Recv-Q with and the connection in a CLOSE_WAIT state that does not seem to abate, even over long periods of time. The reason it is only a partial DOS is that connections can be still made to the outside, but, incoming connections, even from sites allowed via tcpd will hang with a Recv-Q of at least 1 and again a connection state at CLOSE_WAIT. Anyone else notice this with later versions of ssh? How about ssh2? Thanks, Ron DuFresne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ admin & senior consultant: darkstar.sysinfo.com http://darkstar.sysinfo.com "Cutting the space budget really restores my faith in humanity. It eliminates dreams, goals, and ideals and lets us get straight to the business of hate, debauchery, and self-annihilation." -- Johnny Hart testing, only testing, and damn good at it too!
Current thread:
- SSH can be semi DOS'ed R. DuFresne (Dec 24)