VNX-SEC-066: HTTP bearer authentication header

Detects literal HTTP Bearer tokens: a "Bearer <token>" value of 20+ high-entropy characters written into code, scripts or request files.

Field	Value
Rule ID	`VNX-SEC-066`
Severity	High
SARIF level	`error`
Kind	`secrets`
Languages	Any file
CWE	CWE-798
CAPEC	CAPEC-191
ATT&CK	T1552.001
CWSS vector	`CWSS:1.0/TI:H/AP:A/AL:A/IC:N/FC:LT/RP:N/RL:A/AV:I/AS:N/IN:A/SC:A/BI:H/DI:H/EX:H/EC:N/P:H`
Tags	`secrets` `http` `bearer` `credentials`
Source	`internal/sast/rules/vnx-sec-066.rego`

Overview

This rule reports the string Bearer <token> (an Authorization header in a .http file or YAML, a curl -H argument, a headers dict or object, a Header.Set call, a template literal, a constant, or the two-argument .NET new AuthenticationHeaderValue("Bearer", "...")) when the token is at least 20 characters, contains a digit or is a JWT, and has high entropy. The token is masked in the snippet.

It does not report headers built from variables ("Bearer " + token, ${TOKEN}, $(gcloud auth print-access-token), {{ .Values.token }}), low-entropy or placeholder values (invalid_token_format, YOUR_ACCESS_TOKEN, the jwt.io sample token), comment lines, Markdown/reStructuredText/AsciiDoc, and test, fixture, vendored and generated files.

What Gets Flagged

curl -s -H 'Authorization: Bearer <40 random characters>' https://ci.acme-corp.io/api/v4/trigger

session.headers.update({"Authorization": "Bearer <32 random characters>"})

Not flagged:

curl -H "Authorization: Bearer ${GITLAB_TOKEN}" https://gitlab.acme-corp.io/api/v4/projects

Why This Matters

Hardcoded http bearer authentication header 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.

Remediation

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

References

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-066
// nosec vnx-sec-066

Or record an ignore rule: vulnetix ignore add --rule vnx-sec-066 --reason "...". See Suppressing findings.