Re: Lack of environment sanitization in the FreeBSD, OpenBSD, NetBSD dynamic loaders.
>A class of security vulnerabilities has resurfaced in the dynamic loaders
>of FreeBSD, OpenBSD, and NetBSD in the sanitization of environment
>variables for suid and sgid binaries.
In Solaris we have long felt that the dynamic linker should not touch the
environment; instead, the onus is on applications running setuid(0) and
starting subprocesses to strip the appropriate environment variable
(or better, set the environment to a sensible default)
Various bugs of this sort have been fixed in Solaris over the years, in
the set-uid programs. It is just one of the things set-uid program writes
need to be aware of.
As a number of set-uid applications start programs as the user later on,
stripping such environment variables often has undesirably side-effects.
Casper