Redmine before 3.2.9, 3.3.x before 3.3.6, and 3.4.x before 3.4.4 does not block the --config and --debugger flags to the Mercurial hg program, which allows remote attackers to execute arbitrary commands (through the Mercurial adapter) via vectors involving a branch whose name begins with a --config= or --debugger= substring, a related issue to CVE-2017-17536.
https://www.redmine.org/projects/redmine/wiki/Security_Advisories
https://www.redmine.org/issues/27516
https://www.debian.org/security/2018/dsa-4191
https://github.com/redmine/redmine/commit/ca87bf766cdc70179cb2dce03015d78ec9c13ebd
https://github.com/redmine/redmine/commit/9d797400eaec5f9fa7ba9507c82d9c18cb91d02e
https://github.com/redmine/redmine/commit/58ed8655136ff2fe5ff7796859bf6a399c76c678