Bug#158090: security.debian.org: Easy for any user to fake messages into syslog

[Joey Hess <joeyh@debian.org>]

Martin Schulze wrote:
> Even worse, syslogd only reads what is provided on /dev/log.
> 
> The socket is world writable, glibc's syslog() function writes
> to it, from any program.  Restricting its write access to root
> would effectively disable syslogging.

syslogd could use getsockopt(SO_PEERCRED) to get a ucred structure and
work out the user who has opened /dev/log and include that info in the
log somewhere. This would require no special glibc support. If you want
generic code to do that on a unix socket (works on linux, and probably
freebsd, and possibly other bsd's), I can provide it. Where in the log
to put this information without changing the format and breaking a lot of
stuff, I do not know.

-- 
see shy jo