700+ self-hosted Git instances battered in 0-day attacks
www.theregister.com
: More than half of internet-exposed instances already compromised

By ‘Git instances’ they mean Gogs instances that allow open registration. I know most of the community moved from Gogs to Gitea, and then to Forgejo, but thought this was still worth noting.

  • bort@sopuli.xyzEnglish
    94·
    1 day ago

    Here are the steps:

    • The attacker creates a standard Git repository.
    • They commit a single symbolic link pointing to a sensitive target.
    • Using the PutContents API, they write data to the symlink. The system follows the link and overwrites the target file outside the repository.
    • By overwriting .git/config (specifically the sshCommand), the attacker can force the system to execute arbitrary commands–

    amazing.

    • addie@feddit.ukEnglish
      23·
      23 hours ago

      Especially since any version of Git from the last view years has a passionate hatred of symlinks for this reason, which is a bit annoying if you’ve a legit usecase. They’re either very out-of-date, or have done some very foolish customisation…

        • PlexSheep@infosec.pubEnglish
          2·
          3 hours ago

          It’s because of the old notion of “be generous in what you accept and strict in what you send”. I think the error is something about adding more parent directories so that part of your zip file will be extracted above the selected directory. Not all implementations of zip support this “feature”.

          There are also all kinds of stupid ancient features in tar and zip from a time when hard drives were measured in megabytes or less. The latest episode of the open source security podcast talks about it.