| name | sast-lite |
| description | Static security analysis for Python source via AST walking — finds command injection, insecure deserialization, eval/exec, weak crypto, SQL injection, disabled TLS verification, hardcoded secrets and more, each tagged with a CWE. Use when the user asks to "audit this code for vulnerabilities", "run a SAST scan", "security review this Python file", or before merging untrusted code. |
| license | MIT |
SAST Lite
An AST-based static analyzer for Python. Instead of fragile regex matching, it
parses each file into an abstract syntax tree and inspects how dangerous APIs
are actually called — so subprocess.run(cmd, shell=True) is flagged while
subprocess.run(["ls"]) is not. No third-party dependencies.
When to use this skill
- "Audit / security-review this Python code."
- "Run a SAST scan on the project."
- Reviewing a PR or untrusted snippet before running it.
- A pre-merge CI gate for security regressions.
What it detects
| Rule | CWE | Severity |
|---|
eval() / exec() on dynamic input | CWE-95 | critical/high |
os.system / subprocess(shell=True) | CWE-78 | high |
pickle/marshal deserialization | CWE-502 | high |
yaml.load without SafeLoader | CWE-20 | high |
SQL via f-string / concat / .format / % | CWE-89 | high |
requests(verify=False) | CWE-295 | high |
| Hardcoded password/secret literal | CWE-798 | high |
| Weak hash (md5/sha1) | CWE-327 | medium |
tempfile.mktemp | CWE-377 | medium |
Flask(debug=True) | CWE-489 | medium |
Jinja2 autoescape=False | CWE-79 | medium |
assert used for a security check | CWE-617 | medium |
How to run it
python skills/sast-lite/analyzer.py src/
python skills/sast-lite/analyzer.py . --json
python skills/sast-lite/analyzer.py . --min-severity high
Exit codes: 0 clean · 1 issues found · 2 usage/parse error — ready
for CI gating.
Recommended workflow for Claude
- Run with
--json and parse the issue list.
- For each issue, open
path:line and confirm the data flow is genuinely
attacker-controllable (the analyzer is intra-procedural, so it may flag
patterns that are safe in context).
- Propose a concrete fix per finding — e.g. parameterized queries for
py.sql-injection, yaml.safe_load for py.yaml-load,
list-form subprocess calls for py.subprocess-shell.
- Summarize by severity and CWE.
Limitations
This is a lite analyzer: single-file, no cross-function taint tracking. It is
designed for fast, high-signal triage — not a replacement for a full SAST
suite. Treat findings as leads to verify, not automatic verdicts.
