CVE-2021-32724 (published 2021-09-09T21:15Z)

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.

Severity: MEDIUM
CVSS v2 base score: 6.8 (AV:N/AC:M/Au:N/C:P/I:P/A:P)
CVSS v3 base score: 9.9, CRITICAL (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-532
cwe_name: Insertion of Sensitive Information into Log File
description: Information written to log files can be of a sensitive nature and give valuable guidance to an attacker or expose sensitive user information.
extended_description: 
            While logging all information may be helpful during development stages, it is important that logging levels be set appropriately before a product ships so that sensitive user data and system information are not accidentally exposed to potential attackers.
            Different log files may be produced and stored for:
            
               Server log files (e.g. server.log).  This can give information on whatever application left the file. Usually this can give full path names and system information, and sometimes usernames and passwords.
               log files that are used for debugging
            
         
         

Fix information:
repo_url: https://github.com/check-spelling/check-spelling
commit_details: repo_url: https://github.com/check-spelling/check-spelling
author: Josh Soref
author_date: 2021-07-12 15:37:53-04:00
msg: Merge pull request from GHSA-g86g-chm8-7r2p

File handling
repository: repo_url: https://github.com/check-spelling/check-spelling
repo_name: check-spelling/check-spelling
description: Spelling checker action to check spelling in repositories / pull requests / commits
repo_language: Shell
owner: check-spelling