ProactiveSecurityRoadmap
People
Goal
Proactively improve security for Breezy
Requirements
- Run cron as non-root?
- Run dhclient3 as non-root?
- Run dhcpd3 as non-root?
Change unix_chkpwd from suid root to sgid shadow (see [http://bugs.debian.org/155583 #155583])
- Eliminate inetd from base
- Compile-time stack protection?
- Non-executable stack for i386?
Some info already compiled http://ubuntu.com/wiki/UbuntuHardened
Agenda
Pre-Work
- Research privilege requirements of cron
MartinPitt: Parsing the crontabs as normal user and introducing a minimal setuid wrapper for actually executing the commands as the target user will not help to improve security; the remaining stuff (timer and signal handling) does not accept user input and thus is not very error prone. I do not really have a good idea about this. (Note: atd also runs with root privileges, it just hides them a bit; I do not have an idea how to deroot this either, it's the same problem.)
- Research privilege requirements of dhclient3
MartinPitt: normal user with CAP_NET_RAW and CAP_NET_BIND_SERVICE; needs a suid wrapper to call /etc/dhcp3/dhclient-script; prototypical package available; pending security review of dhclient-script (proper quoting, etc.)
- Research privilege requirements of dhcpd3
MartinPitt: normal user with CAP_NET_RAW and CAP_NET_BIND_SERVICE for initialization phase; can be dropped after socket creation; prototypical package available
- Search for implicit dependencies on inetd via netbase
MartinPitt: I compiled a list of all packages in main which use inetd on page InetdUsage.
- Determine requirements for compile-time stack protection in gcc (4.x?)
MartinPitt: mudflap comes with gcc 4.0, but does not help in any way to improve proactive security; [http://www.research.ibm.com/trl/projects/security/ssp/ SSP] currently offers the [http://www.ida.liu.se/~johwi/research_publications/paper_ndss2003_john_wilander.pdf most effective protection], but does not (currently) work with 4.0 and is unlikely to be accepted upstream