CVS 1.12.x, when configured to use SSH for remote repositories, might allow remote attackers to execute arbitrary code via a repository URL with a crafted hostname, as demonstrated by "-oProxyCommand=id;localhost:/bar."
https://security.gentoo.org/glsa/201709-17
https://bugzilla.redhat.com/show_bug.cgi?id=1480800
http://www.ubuntu.com/usn/USN-3399-1
http://www.securityfocus.com/bid/100279