Simple WAIS (SWAIS) 1.11 allows remote attackers to execute arbitrary commands via the shell metacharacters in the search field, as demonstrated using the "|" (pipe) character.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2002-2343
http://www.securityfocus.com/bid/5127
http://www.iss.net/security_center/static/9453.php
http://archives.neohapsis.com/archives/bugtraq/2002-06/0390.html