CVE-2009-5011
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') in pyftpdlib
Race condition in the FTPHandler class in ftpserver.py in pyftpdlib before 0.5.2 allows remote attackers to cause a denial of service (daemon outage) by establishing and then immediately closing a TCP connection, leading to the getpeername function having an ENOTCONN error, a different vulnerability than CVE-2010-3494.
Exploit likelihood
What each source reports
NVD Score used
Race condition in the FTPHandler class in ftpserver.py in pyftpdlib before 0.5.2 allows remote attackers to cause a denial of service (daemon outage) by establishing and then immediately closing a TCP connection, leading to the getpeername function having an ENOTCONN error, a different vulnerability than CVE-2010-3494.
- Record
CVE-2009-5011- CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:N/A:P - Weakness
- CWE-362
- Updated
- 2026-11-02
CVE List No score
Race condition in the FTPHandler class in ftpserver.py in pyftpdlib before 0.5.2 allows remote attackers to cause a denial of service (daemon outage) by establishing and then immediately closing a TCP connection, leading to the getpeername function having an ENOTCONN error, a different vulnerability than CVE-2010-3494.
- Record
CVE-2009-5011- Updated
- 2026-11-02
EUVDEUVD-2010-0026 No score
Race condition in the FTPHandler class in ftpserver.py in pyftpdlib before 0.5.2 allows remote attackers to cause a denial of service (daemon outage) by establishing and then immediately closing a TCP connection, leading to the getpeername function having an ENOTCONN error, a different vulnerability than CVE-2010-3494.
- Record
EUVD-2010-0026- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-62xg-239j-vxg7
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') in pyftpdlib
Race condition in the FTPHandler class in ftpserver.py in pyftpdlib before 0.5.2 allows remote attackers to cause a denial of service (daemon outage) by establishing and then immediately closing a TCP connection, leading to the getpeername function having an ENOTCONN error, a different vulnerability than CVE-2010-3494.
- Record
GHSA-62xg-239j-vxg7- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-362
- Updated
- 2026-11-02
OSVGHSA-62xg-239j-vxg7
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') in pyftpdlib
Race condition in the FTPHandler class in ftpserver.py in pyftpdlib before 0.5.2 allows remote attackers to cause a denial of service (daemon outage) by establishing and then immediately closing a TCP connection, leading to the getpeername function having an ENOTCONN error, a different vulnerability than CVE-2010-3494.
- Record
GHSA-62xg-239j-vxg7- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-362
- Updated
- 2026-11-02
OSV No score
Race condition in the FTPHandler class in ftpserver.py in pyftpdlib before 0.5.2 allows remote attackers to cause a denial of service (daemon outage) by establishing and then immediately closing a TCP connection, leading to the getpeername function having an ENOTCONN error, a different vulnerability than CVE-2010-3494.
- Record
CVE-2009-5011- Updated
- 2026-11-02
OSVDEBIAN-CVE-2009-5011 No score
Race condition in the FTPHandler class in ftpserver.py in pyftpdlib before 0.5.2 allows remote attackers to cause a denial of service (daemon outage) by establishing and then immediately closing a TCP connection, leading to the getpeername function having an ENOTCONN error, a different vulnerability than CVE-2010-3494.
- Record
DEBIAN-CVE-2009-5011- Updated
- 2026-11-02
OSVPYSEC-2010-8 No score
Race condition in the FTPHandler class in ftpserver.py in pyftpdlib before 0.5.2 allows remote attackers to cause a denial of service (daemon outage) by establishing and then immediately closing a TCP connection, leading to the getpeername function having an ENOTCONN error, a different vulnerability than CVE-2010-3494.
- Record
PYSEC-2010-8- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
pyftpdlibPyPI |
through 0.5.1 | 0.5.2 |
python-pyftpdlibDebian:12 |
before 0.5.2-1 | 0.5.2-1 |
python-pyftpdlibDebian:13 |
before 0.5.2-1 | 0.5.2-1 |
python-pyftpdlibDebian:14 |
before 0.5.2-1 | 0.5.2-1 |
pyftpdlibPyPI |
before 0.5.2, plus listed versions 0.2.00.3.00.4.00.5.00.5.1 |
0.5.2 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2009-5011 is a medium vulnerability (CVSS 4.3) in G.rodola Pyftpdlib, published October 19, 2010. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.92%, the 60th percentile. Fixed in pyftpdlib 0.5.2.
References
code.google.com/p/pyftpdlib/source/browse/trunk/HISTORY
nvd.nist.gov/vuln/detail/CVE-2009-5011
github.com/pypa/advisory-database/tree/main/vulns/pyftpdlib/PYSEC-2010-8.yaml
security-tracker.debian.org/tracker/CVE-2009-5011