Buffer overflows in Sierra Half-Life build 1573 and earlier allow remote attackers to execute arbitrary code via (1) a long map command, (2) a long exec command, or (3) long input in a configuration file.
https://exchange.xforce.ibmcloud.com/vulnerabilities/6221
https://exchange.xforce.ibmcloud.com/vulnerabilities/6218
https://euvd.enisa.europa.eu/vulnerability/EUVD-2001-0357
http://archives.neohapsis.com/archives/bugtraq/2001-03/0111.html