Hi, On Thu, Mar 28, 2024 at 05:21:21PM +0100, Michel Verdier wrote: > On 2024-03-28, Marc SCHAEFER wrote: > >> Apparently the root of the security issue is that wall is a setguid > >> program? > > > > a) wall must be able to write to your tty, which is not possible > > if wall is not installed setguid OR if people have sane permissions > > on their terminals (e.g. set to mesg n) > > Found in /etc/login.defs :
Is login.defs actually used by modern Debian with PAM? I seem to recall lots of things in there are controlled by PAM instead now. Looking at all of my sessions, the terminal file for all of them is group writeable despite "TTYPERM 0600" being in /etc/login.defs. $ ls -la $(tty) crw--w---- 1 andy tty 136, 0 Mar 28 16:33 /dev/pts/0 $ mesg is y $ mesg n $ ls -la $(tty) crw------- 1 andy tty 136, 0 Mar 28 16:34 /dev/pts/0 Thanks, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting
