Medium severity · published May 25, 2021
CVE-2021-32638
Github's CodeQL action is provided to run CodeQL-based code scanning on non-GitHub CI/CD systems and requires a GitHub access token to connect to a GitHub repository
4.4
CVSS
0.4%
EPSS
No
On KEV
Description
Github's CodeQL action is provided to run CodeQL-based code scanning on non-GitHub CI/CD systems and requires a GitHub access token to connect to a GitHub repository. The runner and its documentation previously suggested passing the GitHub token as a command-line parameter to the process instead of reading it from a file, standard input, or an environment variable. This approach made the token visible to other processes on the same machine, for example in the output of the `ps` command. If the CI system publicly exposes the output of `ps`, for example by logging the output, then the GitHub access token can be exposed beyond the scope intended. Users of the CodeQL runner on 3rd-party systems, who are passing a GitHub token via the `--github-auth` flag, are affected. This applies to both GitHub.com and GitHub Enterprise users. Users of the CodeQL Action on GitHub Actions are not affected. The `--github-auth` flag is now considered insecure and deprecated. The undocumented `--external-repository-token` flag has been removed. To securely provide a GitHub access token to the CodeQL runner, users should **do one of the following instead**: Use the `--github-auth-stdin` flag and pass the token on the command line via standard input OR set the `GITHUB_TOKEN` environment variable to contain the token, then call the command without passing in the token. The old flag remains present for backwards compatibility with existing workflows. If the user tries to specify an access token using the `--github-auth` flag, there is a deprecation warning printed to the terminal that directs the user to one of the above options. All CodeQL runner releases codeql-bundle-20210304 onwards contain the patches. We recommend updating to a recent version of the CodeQL runner, storing a token in your CI system's secret storage mechanism, and passing the token to the CodeQL runner using `--github-auth-stdin` or the `GITHUB_TOKEN` environment variable. If still using the old flag, ensure that process output, such as from `ps`, is not persisted in CI logs.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
Attack vector
Local
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 34% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CA
Codeql Action · Github
before 20210304 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-32638
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-32638
Patch
https://github.com/github/codeql-action/commit/58defc0652e935f6f2ffc70a82828b98d75476fb
Patch
https://github.com/github/codeql-action/commit/88714e3a60e72ec53caa0e6a203652ee1f3fb1db
Third Party Advisory
https://github.com/github/codeql-action/releases/tag/codeql-bundle-20210304
Exploit
https://github.com/github/codeql-action/security/advisories/GHSA-g36v-2xff-pv5m
Third Party Advisory
https://www.netmeister.org/blog/passing-passwords.html
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