Re: Fw: Anonymous Qmail Denial of Service

[Harald Hanche-Olsen]

- "Sam" <[EMAIL PROTECTED]>:

| 
| > : :    % /var/qmail/bin/qmail-queue
| > : :    ^Z
| > : :    Suspended
| > : :    % kill -9 %1
| > : :    [1]    Killed                 /var/qmail/bin/qmail-queue
| > : :    %
| > : :
| > : :There will be one more zero-length file, owned by qmail, without
| > : :any user identification whatsoever.  It is an exercise for the
| 
| qmail-queue is a setuid program.  Did UNIX change, while I was out
| of town, and you can now send signals to processes of different
| userids?

AFAIK, you can if the program's real uid matches your own.

- [EMAIL PROTECTED] ():

| 4) Could setuid(geteuid()) but that doesn't buy very much.

That should stop the user from killing qmail-queue, methinks.
But perhaps you would normally want the user to have this capability?
For example when you change your mind in the middle of mailing the
output of a program.

- Harald