Re: CVE-2016-0634 -- bash prompt expanding $HOSTNAME

[Jan Schaumann <jschauma () netmeister org>]

John Haxby <john.haxby () oracle com> wrote:
 
> A little while ago, one of our users discovered that by setting the
> hostname to $(something unpleasant), bash would run "something
> unpleasant" when it expanded \h in the prompt string.

To clarify: this is only triggered if the hostname has been set, not the
$HOSTNAME variable, right?

Your subject line suggests setting $HOSTNAME would lead to command
execution, which would be a vulnerability reminiscent of shellshock, but
quickly glancing at the code, it looks like $HOSTNAME is only used if
gethostname(3) returned an empty string?

-Jan