Back to skill

Security audit

Prompt Lint

Security checks for vulnerabilities and agentic risk

Overview

This is an offline prompt-linting tool with CI helpers; the notable code execution is disclosed test-running behavior, not hidden activity.

Safe to install for normal prompt-linting use. Treat the CI verifier like any test runner: run it only on repositories you trust, because it intentionally executes Python tests or self-test commands. If using the curl install path, verify the GitHub source before running the downloaded file.

Vulnerability Patterns
  • Output HandlingUnvalidated Output Injection, Cross-Context Output, Unbounded Output
  • Behavioral ASTexec() Call, eval() Call, Dynamic Import
  • MCP Tool PoisoningHidden Instructions, Unicode Deception, Parameter Description Injection
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
Findings (9)

subprocess module call

Medium
Category
Dangerous Code Execution
Content
def has_self_test(fp):
    r = subprocess.run([sys.executable, fp, "self-test"], capture_output=True, text=True, timeout=30)
    return r.returncode == 0 and "PASS" in r.stdout
Confidence
70% confidence
Finding
subprocess module calls execute external commands. Without careful input validation, this enables command injection.

subprocess module call

Medium
Category
Dangerous Code Execution
Content
# 7 deploy-ready
    ci = os.path.join(os.path.dirname(os.path.abspath(__file__)), "ci_check.py")
    if os.path.isfile(ci) and os.path.isfile(skill):
        r = subprocess.run([sys.executable, ci], cwd=folder, capture_output=True, text=True)
        all_ok &= axis(r.returncode == 0, "deploy-ready (ci/ci_check.py PASS)")
    else:
        all_ok &= axis(True, "deploy-ready (skipped)")
Confidence
70% confidence
Finding
subprocess module calls execute external commands. Without careful input validation, this enables command injection.

subprocess module call

Medium
Category
Dangerous Code Execution
Content
all_ok &= axis(False, "frontmatter (no SKILL.md)")
        all_ok &= axis(False, "docs (no SKILL.md)")
    # 3 compiles
    comp_ok = all(subprocess.run([sys.executable, "-m", "py_compile", fp],
                                capture_output=True).returncode == 0 for fp in files)
    all_ok &= axis(comp_ok, "compiles (py_compile all .py)")
    # 4 self-test (any of 3 valid forms)
Confidence
70% confidence
Finding
subprocess module calls execute external commands. Without careful input validation, this enables command injection.

subprocess module call

Medium
Category
Dangerous Code Execution
Content
tests = [os.path.join(folder, f) for f in os.listdir(folder)
                 if (f.startswith("test_") or f.endswith("_test.py")) and f.endswith(".py")]
        if tests:
            st_ok = all(subprocess.run([sys.executable, t], capture_output=True, text=True,
                                      timeout=30).returncode == 0 for t in tests)
            st_note = f"{len(tests)} test_*.py"
        elif re.search(r"(?im)^test\s*:", skill_txt):
Confidence
70% confidence
Finding
subprocess module calls execute external commands. Without careful input validation, this enables command injection.

Intent-Code Divergence

Medium
Confidence
92% confidence
Finding
The docstring presents the harness as performing a general security check, but the code at L087 restricts secret scanning to files ending in .py collected at L044. This is an intent-level mismatch because the documented verification scope is broader than the actual behavior, potentially misleading users into believing non-Python files are covered.

Unvalidated Output Injection

High
Category
Output Handling
Content
def has_self_test(fp):
    r = subprocess.run([sys.executable, fp, "self-test"], capture_output=True, text=True, timeout=30)
    return r.returncode == 0 and "PASS" in r.stdout
Confidence
95% confidence
Finding
Model output is used without validation or sanitization. Unvalidated output injected into downstream contexts (SQL, shell, HTML) enables injection attacks and arbitrary code execution.

Unvalidated Output Injection

High
Category
Output Handling
Content
all_ok &= axis(False, "frontmatter (no SKILL.md)")
        all_ok &= axis(False, "docs (no SKILL.md)")
    # 3 compiles
    comp_ok = all(subprocess.run([sys.executable, "-m", "py_compile", fp],
                                capture_output=True).returncode == 0 for fp in files)
    all_ok &= axis(comp_ok, "compiles (py_compile all .py)")
    # 4 self-test (any of 3 valid forms)
Confidence
95% confidence
Finding
Model output is used without validation or sanitization. Unvalidated output injected into downstream contexts (SQL, shell, HTML) enables injection attacks and arbitrary code execution.

Unvalidated Output Injection

High
Category
Output Handling
Content
tests = [os.path.join(folder, f) for f in os.listdir(folder)
                 if (f.startswith("test_") or f.endswith("_test.py")) and f.endswith(".py")]
        if tests:
            st_ok = all(subprocess.run([sys.executable, t], capture_output=True, text=True,
                                      timeout=30).returncode == 0 for t in tests)
            st_note = f"{len(tests)} test_*.py"
        elif re.search(r"(?im)^test\s*:", skill_txt):
Confidence
95% confidence
Finding
Model output is used without validation or sanitization. Unvalidated output injected into downstream contexts (SQL, shell, HTML) enables injection attacks and arbitrary code execution.

Unvalidated Output Injection

High
Category
Output Handling
Content
# 7 deploy-ready
    ci = os.path.join(os.path.dirname(os.path.abspath(__file__)), "ci_check.py")
    if os.path.isfile(ci) and os.path.isfile(skill):
        r = subprocess.run([sys.executable, ci], cwd=folder, capture_output=True, text=True)
        all_ok &= axis(r.returncode == 0, "deploy-ready (ci/ci_check.py PASS)")
    else:
        all_ok &= axis(True, "deploy-ready (skipped)")
Confidence
95% confidence
Finding
Model output is used without validation or sanitization. Unvalidated output injected into downstream contexts (SQL, shell, HTML) enables injection attacks and arbitrary code execution.

Static analysis

No suspicious patterns detected.