freebsd security - Sep 2005 - ee using 99% cpu after user ssh session terminates abnormaly

Recently i have been using a dialup 56k account to access the net
and have noticed that when my ssh session times out and I am editing
a file in ` ee ' the system goes to 99% cpu usage and stays like
this till the pid is killed.
This is a standard user account (not root/su)

Would a user be able to create a denial of service condition
on the remote system using this bug?

(sorry if this is posted to the incorrect list)

Details:

System - FreeBSD 5.4-RELEASE-p5

ee using 99% cpu after user session terminates abnormaly
PID reported by top.

The output from ps looks like this

[root@blah][~]$ ps aux| grep 70464
someuser 70464 93.5 0.1 1920 1372 p1- R 7:09PM 687:07.27 ee file


Regards Jason M

On Thu, Sep 08, 2005 at 08:27:13AM +1000, talonz wrote:
> Recently i have been using a dialup 56k account to access the net
> and have noticed that when my ssh session times out and I am editing
> a file in ` ee ' the system goes to 99% cpu usage and stays like
> this till the pid is killed.
> This is a standard user account (not root/su)
> 
> Would a user be able to create a denial of service condition
> on the remote system using this bug?
No more then they could with the ablity to run any other program that
loops.
> (sorry if this is posted to the incorrect list)
> 
> Details:
> 
> System - FreeBSD 5.4-RELEASE-p5
> 
> ee using 99% cpu after user session terminates abnormaly
> PID reported by top.
> 
> The output from ps looks like this
> 
> [root@blah][~]$ ps aux| grep 70464
> someuser 70464 93.5 0.1 1920 1372 p1- R 7:09PM 687:07.27 ee file
I can't seem to trigger this bug on a 7.0 machine either by killing the
client or using tcpdrop to kill the tcp session.

-- Brooks

-- 
Any statement of the form "X is the one, true Y" is FALSE.
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talonz wrote:
> Recently i have been using a dialup 56k account to access the net
> and have noticed that when my ssh session times out and I am editing
> a file in ` ee ' the system goes to 99% cpu usage and stays like
> this till the pid is killed.
> This is a standard user account (not root/su)
This happens all the time on servers I manage. It's a real pain because
it's hard to see the actual load of the machine. We have a dumb hack of
a script that kill these off when they happen.
> Would a user be able to create a denial of service condition
> on the remote system using this bug?
Don't think so, unless there's a process getting starved somewhere, in
which case the DOS would be basically impossible to prevent.

Cheers,
Nate