Forgejo <=16.0.3 Critical RCE

(codeberg.org)

53 points | by weierstass 2 hours ago

14 comments

  • amiga386 1 hour ago
    You should change the URL to https://codeberg.org/forgejo/forgejo/milestone/139655

    > PR: Critical: fix: prevent template expansion from interfering with git repo initialization. When generating a new repository from a template repository, Forgejo clones the template repository, removes the .git folder, performs variable template expansion on files listed in .forgejo/template, and initializes a new git repository. During this process, variable template expansion could be misused in order to create a new .git folder, which git would adopt and incorporate during its initialization of a new git repository. A malicious template repository could be used to read arbitrary data from the Forgejo host, and to execute arbitrary processes on the Forgejo host, as a remote code execution attack. To address this issue, after variable expansion is completed, any existing .git folder is removed from the directory before the git repository is initialized.

  • techknowlogick 45 minutes ago
    Only posting here because I've been asked about it. Gitea is protected against both of these issues.

    (bias note: part of project leadership of Gitea)

    Edit: As a note, security incidents happen to everyone and we shouldn't shame anyone for reporting them, especially as that'd otherwise cause less issues to be reported overall.

    • tredre3 38 minutes ago
      > Gitea is protected against both of these issues.

      Is Gitea's immunity just incidental because it was written by a different person, or is it due to a deliberate defensive system that prevents such bug/mistake from occurring?

  • miguelgrinberg 1 minute ago
    For those on version 15 LTS, this fix was released with v15.0.8.
  • keel-control 1 hour ago
    This was my first thought after they disallowed LLM contributions.

    They may not use AI to check for vulnerabilities but attackers are going to which puts themselves at the disadvantage.

    • burkaman 36 minutes ago
      They did not disallow LLM contributions, and they definitely didn't disallow using LLMs to research security vulnerabilities. They only disallowed projects that are majority LLM-written.

      https://codeberg.org/Codeberg/org/commit/71149c7fc95ccfeae36...

    • bdcravens 36 minutes ago
      Why can't you use an LLM to find vulnerabilities and then hand-code the fix? You don't even have to clean-room implement it; let the LLM write the code, and then reimplement, doing what you can to de-LLM-ify it.
      • omnimus 30 minutes ago
        You can. People on Codeberg use LLMs. They are just against spam of low quality projects generated with LLMs.
    • titularcomment 55 minutes ago
      I really disagree with their acceptable usage policy, but you can't say it with certainity that LLM contributions would be a fix for this. They generate so much noise (as the primary incentive behind an independent LLM scan is often cheap contributor brownie points for your CV) that it also could lead to bogus PRs being approved or helpful PRs being lost in the noise.
    • otherme123 54 minutes ago
      Was this discovered by AI? Is all AI code 100% free of bugs?

      You are implying that just by allowing LLM contributions your product is free of bugs, and the LLM won't introduce new bugs. Of course, if the LLM introduces bugs, the solution is to add another layer of LLM looking for bugs, ad infinitum.

      Another post from today from Shopify, praising LLM to code their frontend, also stated that their LLM generated code is not ready to deploy, and needs to be reviewed:

      > It’s tempting to just point an LLM to the React Native codebase and try to one-shot the same features in native, but it doesn’t work. Even if you ask it to gather as much information as it can up front, freeze that into specs, task files, and then implement it, you end up with a huge amount of unmaintainable code that can’t be shipped. [...] each [build] must prove its behavior with tests, match the running app in a visual review, survive two adversarial code reviewers, and get a human's nod before it's committed and the next one starts.

      • 1matin 47 minutes ago
        > They may not use AI to *check for vulnerabilities*

        you didn't read the comment, did you?

    • striking 47 minutes ago
      Disallowing LLM contributions doesn't disqualify the use of LLMs to identify vulnerabilities.
  • jzebedee 1 hour ago
    Relevant change:

       Security bug fixes
    
        PR: Critical: fix: prevent template expansion from interfering with git repo initialization. When generating a new repository from a template repository, Forgejo clones the template repository, removes the .git folder, performs variable template expansion on files listed in .forgejo/template, and initializes a new git repository. During this process, variable template expansion could be misused in order to create a new .git folder, which git would adopt and incorporate during its initialization of a new git repository. A malicious template repository could be used to read arbitrary data from the Forgejo host, and to execute arbitrary processes on the Forgejo host, as a remote code execution attack. To address this issue, after variable expansion is completed, any existing .git folder is removed from the directory before the git repository is initialized.
    • hephaes7us 1 hour ago
      It looks like this is a bit less concerning if you have turned off open account registration.
  • Macha 1 hour ago
    Since the release notes is currently unreadable due to codeberg rate limits, the two fixes in the release notes are:

    https://codeberg.org/forgejo/forgejo/pulls/14301:

    *Critical:* fix: prevent template expansion from interfering with git repo initialization. When generating a new repository from a template repository, Forgejo clones the template repository, removes the `.git` folder, performs variable template expansion on files listed in `.forgejo/template`, and initializes a new git repository. During this process, variable template expansion could be misused in order to create a new `.git` folder, which git would adopt and incorporate during its initialization of a new git repository. A malicious template repository could be used to read arbitrary data from the Forgejo host, and to execute arbitrary processes on the Forgejo host, as a remote code execution attack. To address this issue, after variable expansion is completed, any existing `.git` folder is removed from the directory before the git repository is initialized.

    https://codeberg.org/forgejo/forgejo/pulls/14301:

    ensure authorization reducer is accessed when checking editable PRs in APIs. When editing a git repo contents through Forgejo's API, a specialized security control is used to permit repository maintainers to edit branches that they do not own when an open pull request with the "allow maintainer edit" option is present. This specialized security control did not take into account API-specific security restrictions, such as repo-specific access tokens. As a result, it was possible for an API access token with restricted permission to make modifications outside of that restricted permission. The specialized security control has been updated to take into account API authentication security restrictions.

    ---

    So if like me you run a private forgejo instance with closed signups and limited repository creation, you can wait for the update. Otherwise maybe take it off the public internet for a bit?

  • rcleveng 1 hour ago
    ``` This git endpoint is seeing a high influx of requests for this repository, to preserve the availability of Codeberg your search request will not be processed. Sorry for the inconvenience and please try again later. ```

    Any mirror?

    • sbx320 1 hour ago
      The PR is still accessible https://codeberg.org/forgejo/forgejo/pulls/14300

          Critical: fix: prevent template expansion from interfering with git repo initialization. When generating a new repository from a template repository, Forgejo clones the template repository, removes the .git folder, performs variable template expansion on files listed in .forgejo/template, and initializes a new git repository. During this process, variable template expansion could be misused in order to create a new .git folder, which git would adopt and incorporate during its initialization of a new git repository. A malicious template repository could be used to read arbitrary data from the Forgejo host, and to execute arbitrary processes on the Forgejo host, as a remote code execution attack. To address this issue, after variable expansion is completed, any existing .git folder is removed from the directory before the git repository is initialized.
  • nightpool 19 minutes ago
    What does the error message mean by "Your search request"? Why is viewing a single file in a repository considered a search request? That smells like poor caching somewhere
  • PaoloBarbolini 1 hour ago
    If you are self-hosting Forgejo and haven't done it yet, consider creating a Codeberg account and following https://codeberg.org/forgejo/security-announcements/issues
    • xyst 49 minutes ago
      Updates also posted to #forgejo-chat:matrix.org channel.
  • innocent_name 29 minutes ago
    The opex and security fine costs of moving off managed services like GitHub/GitLab are catching up.
  • Sphax 1 hour ago
    Can't load the page but hopefully it's on an endpoint sitting behind my Tinyauth protection.
  • dboreham 28 minutes ago
    Quick note that this is not an RCE in the typical sense that I can rock up to a Forgejo installation and execute code on the server. The attack vector here is via a template repo specified when initializing a new repo. The template repo could contain malicious code that then executes on the host server. So if you don't create new repos from mystery meat template repos, you should be ok.
    • nightpool 16 minutes ago
      Are you sure? The change says "A malicious template repository could be used to read arbitrary data from the Forgejo host" (emphasis added). Couldn't an attacker create a template repo and then immediately create a new repo from their own template, causing the Forgejo process to execute their template code on the server?
  • bakugo 19 minutes ago
    Trying to open any codeberg.org page from my main Helium browser results in a 403 just saying "Bye". Opening in Chrome or Firefox works fine. Very confusing.