test: add cleartext-sensitive-storage fixture (CWE-312)

docs/VULNERABILITY_CATALOG.md

@@ -7,12 +7,12 @@ from each file's header comment, so this page cannot drift from the source.
 
 ## Totals
 
-- **Test cases:** 124
-- **Expected detections:** 124
-- **`VULNERABLE:` markers:** 231 (individual lines a scanner should flag)
-- **`SAFE:` markers:** 141 (lines a scanner must not flag — the false-positive control group)
+- **Test cases:** 125
+- **Expected detections:** 125
+- **`VULNERABLE:` markers:** 233 (individual lines a scanner should flag)
+- **`SAFE:` markers:** 142 (lines a scanner must not flag — the false-positive control group)
 - **Languages:** 8 — dotenv, go, java, javascript, json, python, ruby, text
-- **CWE categories:** 87 — CWE-20, CWE-22, CWE-78, CWE-79, CWE-89, CWE-90, CWE-94, CWE-95, CWE-113, CWE-117, CWE-129, CWE-190, CWE-201, CWE-203, CWE-208, CWE-209, CWE-256, CWE-287, CWE-288, CWE-291, CWE-295, CWE-306, CWE-307, CWE-311, CWE-319, CWE-321, CWE-326, CWE-327, CWE-329, CWE-330, CWE-338, CWE-345, CWE-346, CWE-347, CWE-352, CWE-362, CWE-377, CWE-384, CWE-400, CWE-409, CWE-434, CWE-441, CWE-460, CWE-472, CWE-475, CWE-480, CWE-488, CWE-489, CWE-502, CWE-506, CWE-509, CWE-512, CWE-521, CWE-522, CWE-525, CWE-532, CWE-598, CWE-601, CWE-602, CWE-611, CWE-613, CWE-614, CWE-620, CWE-639, CWE-640, CWE-643, CWE-681, CWE-693, CWE-732, CWE-759, CWE-776, CWE-798, CWE-835, CWE-862, CWE-863, CWE-915, CWE-916, CWE-918, CWE-922, CWE-942, CWE-943, CWE-1021, CWE-1236, CWE-1321, CWE-1333, CWE-1336, CWE-1357
+- **CWE categories:** 88 — CWE-20, CWE-22, CWE-78, CWE-79, CWE-89, CWE-90, CWE-94, CWE-95, CWE-113, CWE-117, CWE-129, CWE-190, CWE-201, CWE-203, CWE-208, CWE-209, CWE-256, CWE-287, CWE-288, CWE-291, CWE-295, CWE-306, CWE-307, CWE-311, CWE-312, CWE-319, CWE-321, CWE-326, CWE-327, CWE-329, CWE-330, CWE-338, CWE-345, CWE-346, CWE-347, CWE-352, CWE-362, CWE-377, CWE-384, CWE-400, CWE-409, CWE-434, CWE-441, CWE-460, CWE-472, CWE-475, CWE-480, CWE-488, CWE-489, CWE-502, CWE-506, CWE-509, CWE-512, CWE-521, CWE-522, CWE-525, CWE-532, CWE-598, CWE-601, CWE-602, CWE-611, CWE-613, CWE-614, CWE-620, CWE-639, CWE-640, CWE-643, CWE-681, CWE-693, CWE-732, CWE-759, CWE-776, CWE-798, CWE-835, CWE-862, CWE-863, CWE-915, CWE-916, CWE-918, CWE-922, CWE-942, CWE-943, CWE-1021, CWE-1236, CWE-1321, CWE-1333, CWE-1336, CWE-1357
 
 ## How coverage is scored
 
@@ -103,6 +103,7 @@ counts as a detection. See `docs/SCANNER_INTEGRATION.md`.
 
 | Test case | File | CWE | Severity | Expected | Markers |
 |---|---|---|---|---|---|
+| Cleartext storage of sensitive information in a local file | [`cleartext-sensitive-storage.py`](../vulns/python/cleartext-sensitive-storage.py) | CWE-312 | high | yes | 2 vuln / 1 safe |
 | Sensitive data sent over an unencrypted channel | [`cleartext-transmission.py`](../vulns/python/cleartext-transmission.py) | CWE-319 | high | yes | 5 vuln / 1 safe |
 | Session cookie missing Secure flag over HTTPS | [`cookie-without-secure.py`](../vulns/python/cookie-without-secure.py) | CWE-614 | medium | yes | 3 vuln / 2 safe |
 | CSRF via missing anti-CSRF token on state-changing POST | [`csrf-missing-token.py`](../vulns/python/csrf-missing-token.py) | CWE-352 | high | yes | 3 vuln / 1 safe |

vulns/VULNERABILITY_CATALOG.json

@@ -2,10 +2,10 @@
   "schema": "threatcrush-testbed-catalog/1",
   "note": "Generated by scripts/generate-catalog.py \u2014 do not edit by hand.",
   "totals": {
-    "test_cases": 124,
-    "expected_detections": 124,
-    "vulnerable_markers": 231,
-    "safe_markers": 141,
+    "test_cases": 125,
+    "expected_detections": 125,
+    "vulnerable_markers": 233,
+    "safe_markers": 142,
     "languages": [
       "dotenv",
       "go",
@@ -50,6 +50,7 @@
       "CWE-306",
       "CWE-307",
       "CWE-311",
+      "CWE-312",
       "CWE-319",
       "CWE-321",
       "CWE-326",
@@ -1569,6 +1570,30 @@
         34
       ]
     },
+    {
+      "id": "py-cleartext-sensitive-storage",
+      "file": "vulns/python/cleartext-sensitive-storage.py",
+      "title": "Cleartext storage of sensitive information in a local file",
+      "category": "python",
+      "language": "python",
+      "cwe": "CWE-312",
+      "cwes": [
+        "CWE-312"
+      ],
+      "severity": "high",
+      "expected_detection": true,
+      "description": "Sensitive data (session tokens, passwords, API keys) is written",
+      "detection_target": "open(..., \"w\") / Path.write_text / json.dump / yaml.dump",
+      "safe_guard": "All code is wrapped in `if False:` (unreachable dead code). No",
+      "attribution": "line",
+      "vulnerable_lines": [
+        31,
+        39
+      ],
+      "safe_lines": [
+        51
+      ]
+    },
     {
       "id": "py-cleartext-transmission",
       "file": "vulns/python/cleartext-transmission.py",

vulns/python/cleartext-sensitive-storage.py

@@ -0,0 +1,55 @@
+"""
+@id py-cleartext-sensitive-storage
+@test-case Cleartext storage of sensitive information in a local file
+@cwe CWE-312
+@severity high
+@language python
+@expected-detection true
+@description Sensitive data (session tokens, passwords, API keys) is written
+             to a local file in cleartext with no access restriction. Any
+             process with the app's user can read the file. The safe
+             counterpart encrypts the payload or stores the secret via a
+             restricted 0o600 file with key rotation. Detection target is a
+             secret-shaped value written to a filesystem sink with no
+             encryption step.
+@safe-guard All code is wrapped in `if False:` (unreachable dead code). No
+            file is created; the secret literal is synthetic and protects
+            nothing.
+@detection-target open(..., "w") / Path.write_text / json.dump / yaml.dump
+                  where the payload contains a credential/token/session-shaped
+                  value and the write mode is not restricted/encrypted.
+
+NEVER RUN IN PRODUCTION - intentional test case for scanner validation.
+"""
+
+import json
+import os
+
+
+def cache_session_token_vulnerable(session_id: str) -> None:
+    if False:
+        # VULNERABLE: CWE-312 - session token persisted in cleartext
+        with open("/tmp/internal/session.txt", "w") as fh:  # noqa: S108
+            fh.write(session_id)
+    return None
+
+
+def dump_config_vulnerable(api_key: str) -> None:
+    if False:
+        # VULNERABLE: CWE-312 - API key dumped to JSON cleartext
+        with open("config/runtime.json", "w") as fh:
+            json.dump({"api_key": api_key}, fh)
+    return None
+
+
+def cache_session_token_safe(session_id: str) -> None:
+    """Safe counterpart - the scanner should NOT flag this.
+
+    @expected-detection false
+    """
+    if False:
+        # SAFE: restricted perms + only encrypted bytes persisted
+        fd = os.open("/tmp/internal/session.dat", os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
+        with os.fdopen(fd, "wb") as fh:
+            fh.write(b"encrypted-bytes-here")
+    return None