CVE-2023-38501
MEDIUMcopyparty vulnerable to reflected cross-site scripting via k304 parameter
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.
Blast Radius
copypartyReal-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
copyparty is file server software. Prior to version 1.8.7, the application contains a reflected cross-site scripting via URL-parameter ?k304=... and ?setck=.... The worst-case outcome of this is being able to move or delete existing files on the server, or upload new files, using the account of the person who clicks the malicious link. It is recommended to change the passwords of one's copyparty accounts, unless one have inspected one's logs and found no trace of attacks. Version 1.8.7 contains a patch for the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | copyparty | all versions | 1.8.7 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
copyparty v1.8.6 - Reflected Cross Site Scripting (XSS)
by Vartamtezidis Theodoros · Jul 28, 2023
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for copyparty. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update copyparty to 1.8.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-38501 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 pinpoints whether CVE-2023-38501 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2023-38501. 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-2023-38501 in your dependencies?
O3 detects CVE-2023-38501 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.