Re: Executing the kill command from within an suid script.
Jeff Rouse/NCO/CEtv [[EMAIL PROTECTED]] quoth: * *I have been an SA and DBA for 7 years and have worked in a lot of different *environments for several companies and I didn't go into apoplectic shock at *my suggestion :-) Look at the suidperl source code, you will :) suid, even if root is not the target id, is inherently insecure because of how suid operates. I hear XML-RPC is the new wave of web services for things such as this so you might have a look just for fun. e. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Executing the kill command from within an suid script.
Jeff Rouse/NCO/CEtv [[EMAIL PROTECTED]] quoth: * *Basically the process I wish to send a kill signal to is a redirector for *squid. The process is owned by the squid user. The kill signal makes the *redirector dump statistics about itself to a file. I want to run a script *from my cgi-bin which will run as user nobody that can send the kill signal *to the process that squid owns. The script works fine when run as root. Sometimes things don't work for good reason. Having a process owned by 'nobody' able to kill a real user process? An SA would go into apoplectic shock right about now...oh, and from the web too...gads, call the paramedics. The feature known as 'suidperl' is what you are looking for most likely. Also, your system may have suid restrictions such as -nosuid with automount or NFS on some of the filesystems, etc. There have been a couple of CERT advisories in the last few years on the dangers of using suidperl and suid in general is a less than stellar idea for anything, unless you are aware of the risks involved. *Does anyone know how I can get my perl script to run as another user and *issue a kill signal to a process? http://perldoc.cpan.org/ and read the perlsec pod Also, Web Security by Lincoln Stein, ISBN: 0201634899, may be a good introduction for you. He also maintains the WWW Security FAQ that has a load of good info http://www.w3.org/Security/Faq/index.html#contents. Don't run suid if you don't have to-ever. Ask yourself why nobody needs to kill real system user processes and perhaps either redesign or try something else. Usually it's a matter of being lazy and lazy doesn't win when you want a reasonably secure system. e. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Executing the kill command from within an suid script.
Hi Elaine Thanks for the info. After spending loads of time searching the web I decided to send an email to this group. As usual I found the answer about an hour later. Basically the suggestion in the perl security stuff of writing just a .c wrapper with an exec statement doesn't work, or at least in my case. I also added in a setuid and seteuid statement and then it worked. I don't really like setuid programs but as it will not be running as root their is not too much chance of it causing problems. The cgi-bin that I will be running this from is on a sys-admin intranet. The web server runs as user nobody. I did not set this up and so I am not keen on changing it. And even it was changed to another user it would make little difference to my suid problem unless I ran it as the squid user which I would think is even less secure as it opens up all the squid processes and not just the redirector children. The perl script is quit specific as to what it is killing and does not take parameters. I have been an SA and DBA for 7 years and have worked in a lot of different environments for several companies and I didn't go into apoplectic shock at my suggestion :-) Thanks again for the advice. Jeff. Elaine -HFB- Ashton To: Jeff Rouse/NCO/CEtv [EMAIL PROTECTED] elaine@chaos. cc: [EMAIL PROTECTED] wustl.edu Subject: Re: Executing the kill command from within an suid script. 08/07/2001 12:07 AM Jeff Rouse/NCO/CEtv [[EMAIL PROTECTED]] quoth: * *Basically the process I wish to send a kill signal to is a redirector for *squid. The process is owned by the squid user. The kill signal makes the *redirector dump statistics about itself to a file. I want to run a script *from my cgi-bin which will run as user nobody that can send the kill signal *to the process that squid owns. The script works fine when run as root. Sometimes things don't work for good reason. Having a process owned by 'nobody' able to kill a real user process? An SA would go into apoplectic shock right about now...oh, and from the web too...gads, call the paramedics. The feature known as 'suidperl' is what you are looking for most likely. Also, your system may have suid restrictions such as -nosuid with automount or NFS on some of the filesystems, etc. There have been a couple of CERT advisories in the last few years on the dangers of using suidperl and suid in general is a less than stellar idea for anything, unless you are aware of the risks involved. *Does anyone know how I can get my perl script to run as another user and *issue a kill signal to a process? http://perldoc.cpan.org/ and read the perlsec pod Also, Web Security by Lincoln Stein, ISBN: 0201634899, may be a good introduction for you. He also maintains the WWW Security FAQ that has a load of good info http://www.w3.org/Security/Faq/index.html#contents. Don't run suid if you don't have to-ever. Ask yourself why nobody needs to kill real system user processes and perhaps either redesign or try something else. Usually it's a matter of being lazy and lazy doesn't win when you want a reasonably secure system. e. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] = This message has been scanned for viruses by AUSTAR Communication's antivirus and content checking applications. Austar Communications = *** This email and any files transmitted with it, are confidential and is intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error, please notify the system manager. This footnote also
Executing the kill command from within an suid script.
Hi I would like to run an suid perl script that among other things sends a kill -USR1 signal to a process. I have read about Perl tainting variables for security etc and to write a .c wrapper. I did this but still get an error running system() calls from within my perl script. I changed the system call to do a fork and then exec the kill in the child but this still errors with the statement : Insecure dependency in exec while running setuid at . The C executable is setuid but the perl script is not. Basically the process I wish to send a kill signal to is a redirector for squid. The process is owned by the squid user. The kill signal makes the redirector dump statistics about itself to a file. I want to run a script from my cgi-bin which will run as user nobody that can send the kill signal to the process that squid owns. The script works fine when run as root. Does anyone know how I can get my perl script to run as another user and issue a kill signal to a process? Thankyou. *** This email and any files transmitted with it, are confidential and is intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error, please notify the system manager. This footnote also confirms that this email message has been scanned by AUSTAR Communications content and virus scanning applications for the presence of computer viruses. *** -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
