CVE-2009-5013 — pyftpdlib
CVE-2009-5013 is a CWE-399 vulnerability in pyftpdlib. A fix is available for pyftpdlib — see the affected versions and patch details below.
Uncontrolled Resource Consumption in pyftpdlib
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
pyftpdlibReal-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
Memory leak in the on_dtp_close function in ftpserver.py in pyftpdlib before 0.5.2 allows remote authenticated users to cause a denial of service (memory consumption) by sending a QUIT command during a data transfer.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pyftpdlib | all versions | 0.5.2pip install --upgrade 'pyftpdlib==0.5.2' |
Affected Products
pyftpdlibg.rodolaDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pyftpdlib, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pyftpdlib to 0.5.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2009-5013 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is CVE-2009-5013 in your dependencies?
Find it across PyPI, including transitive dependencies.