http_transport.c in Fossil before 2.4, when the SSH sync protocol is used, allows user-assisted remote attackers to execute arbitrary commands via an ssh URL with an initial dash character in the hostname, a related issue to CVE-2017-9800, CVE-2017-12836, CVE-2017-12976, CVE-2017-14176, CVE-2017-16228, CVE-2017-1000116, and CVE-2017-1000117.
https://www.fossil-scm.org/xfer/info/1f63db591c77108c
https://www.fossil-scm.org/xfer/doc/trunk/www/changes.wiki#v2_4