GitHub Git LFS before 2.1.1 allows remote attackers to execute arbitrary commands via an ssh URL with an initial dash character in the hostname, located on a "url =" line in a .lfsconfig file within a repository.
https://github.com/git-lfs/git-lfs/releases/tag/v2.1.1
https://github.com/git-lfs/git-lfs/pull/2242
https://confluence.atlassian.com/sourcetreekb/sourcetree-security-advisory-2018-01-24-942834324.html