Xinuos (formerly SCO) Openserver v5 and v6 allows attackers to execute arbitrary commands via shell metacharacters in outputform or toclevels parameter to cgi-bin/printbook.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2020-18179
http://packetstormsecurity.com/files/160635/SCO-Openserver-5.0.7-Command-Injection.html