We have just released another security advisory detailing multiple security vulnerabilities in GitLab and gitlab-shell. Users of GitLab Enterprise Edition should update gitlab-shell to version 1.7.8 immediately, and update GitLab to version 6.2.1-ee. If you are unable to update your GitLab EE installation to version 6.2.1-ee you should apply this patch (link to private GitLab EE repository).
For more information or if you are running GitLab CE, please see the advisory on blog.gitlab.org.
Update (14 Nov 2013 18:07:37 CET): refer CE users to blog.gitlab.org.