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Insertion of Sensitive Information into Log File

CVE-2021-32724

High
9.9/10

Summary

check-spelling is a github action which provides CI spell checking. In affected versions and for a repository with the [check-spelling action](https://github.com/marketplace/actions/check-spelling) enabled that triggers on `pull_request_target` (or `schedule`), an attacker can send a crafted Pull Request that causes a `GITHUB_TOKEN` to be exposed. With the `GITHUB_TOKEN`, it's possible to push commits to the repository bypassing standard approval processes. Commits to the repository could then steal any/all secrets available to the repository. As a workaround users may can either: [Disable the workflow](https://docs.github.com/en/actions/managing-workflow-runs/disabling-and-enabling-a-workflow) until you've fixed all branches or Set repository to [Allow specific actions](https://docs.github.com/en/github/administering-a-repository/managing-repository-settings/disabling-or-limiting-github-actions-for-a-repository#allowing-specific-actions-to-run). check-spelling isn't a verified creator and it certainly won't be anytime soon. You could then explicitly add other actions that your repository uses. Set repository [Workflow permissions](https://docs.github.com/en/github/administering-a-repository/managing-repository-settings/disabling-or-limiting-github-actions-for-a-repository#setting-the-permissions-of-the-github_token-for-your-repository) to `Read repository contents permission`. Workflows using `check-spelling/check-spelling@main` will get the fix automatically. Workflows using a pinned sha or tagged version will need to change the affected workflows for all repository branches to the latest version. Users can verify who and which Pull Requests have been running the action by looking up the spelling.yml action in the Actions tab of their repositories, e.g., https://github.com/check-spelling/check-spelling/actions/workflows/spelling.yml - you can filter PRs by adding ?query=event%3Apull_request_target, e.g., https://github.com/check-spelling/check-spelling/actions/workflows/spelling.yml?query=event%3Apull_request_target.

  • LOW
  • NETWORK
  • HIGH
  • CHANGED
  • NONE
  • LOW
  • HIGH
  • HIGH

CWE-532 - Insertion of Sensitive Information into Log File

It's quite common for applications to save logs. For example, whenever a user requests a resource from a particular website, the web server writes information about the request to a log file. These files are helpful for identifying abnormal system activity, bugs, and evaluating the security controls of the application. Security of log files is critical for the overall security of the application and its confidential resources. An application that lacks appropriate logging levels can expose sensitive user data and system information stored on the log files to malicious users. This info can be exploited to compromise your system.

References

Advisory Timeline

  • Published