Bugtraq mailing list archives
RE: ADV/EXP: netkit <=0.17 in.telnetd remote buffer overflow
From: "Vidovic,Zvonimir,VEVEY,GL-IS/CIS" <Zvonimir.Vidovic () nestle com>
Date: Fri, 10 Aug 2001 10:24:06 +0200
fortunately, the debian guys did this by default in their excellent distro, this prevents lots of exploitable machines to be readily accessible. However, apt-get update and upgrade does fix the breach.
-----Original Message----- From: psz () maths usyd edu au [SMTP:psz () maths usyd edu au] Sent: Thursday, 9. August 2001 23:38 To: bugtraq () securityfocus com; zen-parse () gmx net Subject: Re: ADV/EXP: netkit <=0.17 in.telnetd remote buffer overflow zen-parse () gmx net wrote:If the user has local access to the system, it is possible to get the program to set arbitrary environment variables in the environment of /bin/login. e.g. LD_PRELOAD=/tmp/make-rootshell.soTo protect against this (and possible bad environment processing within telnetd itself), create some otherwise unused group and make /bin/login setgid to that: # chown root._login_ /bin/login # chmod 6711 /bin/login # ls -l /bin/login -rws--s--x 1 root _login_ 24752 Aug 25 2000 /bin/login (Since telnetd runs as root, login has getuid==geteuid so the OS may follow LD_PRELOAD and similar variables. Using this login has getgid!=getegid and the OS should disallow such trickery.) Paul Szabo - psz () maths usyd edu au http://www.maths.usyd.edu.au:8000/u/psz/ School of Mathematics and Statistics University of Sydney 2006 Australia
Current thread:
- ADV/EXP: netkit <=0.17 in.telnetd remote buffer overflow zen-parse (Aug 09)
- Re: ADV/EXP: netkit <=0.17 in.telnetd remote buffer overflow bendik (Aug 09)
- <Possible follow-ups>
- Re: ADV/EXP: netkit <=0.17 in.telnetd remote buffer overflow Paul Szabo (Aug 09)
- RE: ADV/EXP: netkit <=0.17 in.telnetd remote buffer overflow Vidovic,Zvonimir,VEVEY,GL-IS/CIS (Aug 10)