On 2006-03-04 09:00, Kovesdan Gabor <[EMAIL PROTECTED]> wrote: >Giorgos Keramidas wrote: >>On 2006-03-04 00:44, Kovesdan Gabor <[EMAIL PROTECTED]> wrote: >>> Hello, >>> look at this: >>> >>> [EMAIL PROTECTED] w >>> 12:41AM up 82 days, 10:05, 0 users, load averages: 0.00, 0.00, 0.00 >>> USER TTY FROM LOGIN@ IDLE WHAT >>> [EMAIL PROTECTED] >>> >>> Where am I? :) I don't know exactly how it happened, but I'll >>> investigate, I have an idea and I'll report if I find out. >> >> Some programs may tweak wtmp to `hide' users that are actively logged >> in. One program that I know can do this is screen(1). Hitting ``^A L'' >> here, between successive `w' invocations, I can see this: >> >> [EMAIL PROTECTED]:/root# w >> 2:04AM up 2:10, 1 user, load averages: 0.07, 0.16, 0.19 >> USER TTY FROM LOGIN@ IDLE WHAT >> [EMAIL PROTECTED]:/root# w >> 2:05AM up 2:11, 2 users, load averages: 0.03, 0.14, 0.17 >> USER TTY FROM LOGIN@ IDLE WHAT >> root pts/0 :0:S.0 2:05AM - w >> [EMAIL PROTECTED]:/root# > > And what do the other logged in users see?
Only what `w' can see too. > With my method I can completely hide, nobody can see me logged in. What is your method? I haven't seen any description of how *you* ended up not being logged in. Are you using screen(1) or another program that tweaks /var/log/wtmp? Which program? Have you found out why your login seems record in wtmp was marked as logged out? > So I think it might be an opportunity to abusing. I'll send a PR soon, > I just wanted to know before if somebody already knows about this > trick. I don't think this is a bug. The permissions of ``/var/log/wtmp'' are: $ ls -ld /var/log/wtmp -rw-r--r-- 1 root wheel - 8052 Mar 4 16:51 /var/log/wtmp What a bug about this would report is that set-user-id programs, like screen(1), can do all sorts of nasty things if abused. This isn't exactly a bug, but common knowledge. - Giorgos _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"