Vulnerability Details : CVE-2021-32724
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.
Products affected by CVE-2021-32724
- cpe:2.3:a:check-spelling:check-spelling:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-32724
0.10%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 42 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-32724
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
6.8
|
MEDIUM | AV:N/AC:M/Au:N/C:P/I:P/A:P |
8.6
|
6.4
|
NIST | |
9.9
|
CRITICAL | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
3.1
|
6.0
|
GitHub, Inc. |
CWE ids for CVE-2021-32724
-
The product writes sensitive information to a log file.Assigned by: security-advisories@github.com (Primary)
References for CVE-2021-32724
-
https://github.com/check-spelling/check-spelling/commit/436362fc6b588d9d561cbdb575260ca593c8dc56
Merge pull request from GHSA-g86g-chm8-7r2p · check-spelling/check-spelling@436362f · GitHubPatch;Third Party Advisory
-
https://github.com/check-spelling/check-spelling/security/advisories/GHSA-g86g-chm8-7r2p
check-spelling workflow vulnerable to GITHUB_TOKEN leakage via symlink attack · Advisory · check-spelling/check-spelling · GitHubMitigation;Third Party Advisory
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