> Tim <mailto:tim-secur...@sentinelchicken.org> > Thursday, September 25, 2014 5:55 PM > ... > > So dhclient calls /bin/bash explicitly? I didn't look that deeply > into it, but my /bin/sh is dash and nothing breaks, so if it really > does depend on bash, it would need to do that.
it's like this: > vixie@linux1:~$ uname -srm > Linux 3.2.0-4-amd64 x86_64 > vixie@linux1:~$ head -1 /sbin/dhclient-script > #!/bin/bash i'm told that this is somewhat common, which probably means that not all shells are good enough for this script. on debian, /bin/sh is "dash" which may be an example of "not good enough to run this script". on systems like red hat and mac osx where /bin/sh just is bash, it's the same effect but dhclient-script begins #!/bin/sh instead. here's a POC: https://www.trustedsec.com/september-2014/shellshock-dhcp-rce-proof-concept/ -- Paul Vixie _______________________________________________ Sent through the Full Disclosure mailing list http://nmap.org/mailman/listinfo/fulldisclosure Web Archives & RSS: http://seclists.org/fulldisclosure/
