VNX-SEC-079: GitHub fine-grained personal access token

Field	Value
Rule ID	VNX-SEC-079
Severity	Critical
SARIF level	error
Kind	secrets
Languages	Any file
CWE	CWE-798
CAPEC	CAPEC-191
ATT&CK	T1552.001
CWSS vector	CWSS:1.0/TI:C/AP:A/AL:A/IC:N/FC:LT/RP:N/RL:A/AV:I/AS:N/IN:A/SC:A/BI:C/DI:H/EX:H/EC:N/P:W
Tags	secrets github credentials
Source	internal/sast/rules/vnx-sec-079.rego

Overview

This rule reports a GitHub fine-grained personal access token, github_pat_ followed by 22 alphanumeric characters, an underscore and 59 more, on its own, assigned, in an Authorization header or inside a clone URL. The token is redacted in the finding’s snippet.

Why This Matters

Hardcoded github fine-grained personal access token values are routinely scraped by automated bots within minutes of a public push, and then used to access the account, exfiltrate data, or pivot into downstream services. Once the credential is in git history it is permanently in third-party hands.

What Gets Flagged

// FLAGGED
export const octokit = new Octokit({ auth: "github_pat_<22 characters>_<59 characters>" });

# FLAGGED: token inside a clone URL
git clone https://x-access-token:github_pat_<22>_<59>@github.com/acme/infra.git

Not flagged:

• Classic ghp_ tokens (VNX-SEC-004 reports them).
• Prefix checks (strings.HasPrefix(t, "github_pat_")), truncated tokens and placeholders (github_pat_xxxx...).
• CI-secret references (${{ secrets.RELEASE_PAT }}).
• Test, fixture, vendored and generated files.

VNX-SEC-004 also reports these tokens as part of its wider GitHub/GitLab set.

Remediation

1. Revoke the leaked credential in the provider’s console immediately.
2. Replace with a short-lived alternative, OAuth 2.0 access tokens, IAM role assumption, OIDC federation, wherever the platform supports it.
3. Store the new credential in a secrets manager (AWS Secrets Manager, HashiCorp Vault, GitHub Actions secrets, Doppler).
4. Audit the provider’s access logs for activity you did not initiate between the leak and the revocation.
5. Purge from git history with git filter-repo or BFG, then re-scan with gitleaks/truffleHog to confirm no other secrets remain.
6. Enable push protection so future commits are blocked at the developer machine.

References

• CWE-798: Use of Hard-coded Credentials
• gitleaks
• truffleHog
• OWASP Credentials Management Cheat Sheet
• MITRE ATT&CK T1552.001 – Credentials In Files
• git-filter-repo

Suppressing this rule

Put a nosec comment on the line, or on line 1 to cover the whole file. Use the comment marker of the file’s language (#, //, -- or ;):

# nosec vnx-sec-079
// nosec vnx-sec-079

Or record an ignore rule: vulnetix ignore add --rule vnx-sec-079 --reason "...". See Suppressing findings.