COMMAND
in.talkd(8)
SYSTEMS AFFECTED
System using an unpatched in.talkd.
PROBLEM
in.talkd does not filter out escape characters passed to it as the
address of the calling party and prints them on the screen. This
can be used to garble a users screen, or if using a terminal that
supports echo back escape sequences it can be used to run
commands as the user at the terminal.
SOLUTION
Set msgs to no, patch in.talkd to filter out escape characters
from from foreing address, or turn off in.talkd. Here are the
diff for the process.c from the bsd source code:
90a92,96
> if (strchr(mp->l_name,27)) {
> syslog(LOG_NOTICE,"flash received. Aborting);
> rp->answer = FAILED;
> return;
> }