Hi, Sorry, but maybe i'll resend this email (I was very sleepy while writing prev leter). Hi, I have just discoverd that there is a bug in sshd allowing ordinary user to be showed as not logged in while logged in. You should simply ssh to remote host and run command "bash". One that's not so good, is that you will not have the controlling terminal, but ... Look at this: --- debian:~# w 9:51pm up 10 min, 3 users, load average: 0.00, 0.02, 0.00 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT root tty1 9:41pm 12.00s 0.81s 0.63s ssh -l root tty2 9:44pm 6:30 0.22s 0.06s ppf root tty3 9:44pm 0.00s 0.26s 0.04s w debian:~# ssh -lgreg localhost /bin/bash gregat_private's password: finger Login Name Tty Idle Login Time Office Office Phone root root *1 Apr 18 21:41 root root *2 6 Apr 18 21:44 root root *3 Apr 18 21:44 whoami greg --- This means that the potiential unprivialged user can use any account in the system (hacked or so), and it's possible that root will not know what is happening (or will know when it's too late ;-). Vulnerable: all known by me ssh versions (<=1.2.26) Solution: If this bug is as serious as i think i'll write a patch. Regards, Greg ******************************************************************************* * Grzegorz Stelmaszek * For my public PGP key finger * gregat_private * gregat_private * http://www.lighting.ml.org * ******************************
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