CVE-2009-5011

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.

Published: 2010-10-19 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2009-5011 is rated Low Risk (37.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.93%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2009-5011

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.44% 0.93% +0.50%
2 2025-03-30 0.48% 0.44% -0.04%
3 2025-03-29 — 0.48% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2009-5011

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2009-5011

GitHub Security Advisory for CVE-2009-5011

GHSA-62xg-239j-vxg7 · Severity: medium · Ecosystem: pip — Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') in pyftpdlib

OS Trackers for CVE-2009-5011

vendor priority summary link
debian not yet assigned CVE-2009-5011 not yet assigned priority: Debian including 1 source packages (python-pyftpdlib), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2009-5011

Affected software / configurations for CVE-2009-5011

Vendor Product Version Raw CPE
g.rodola pyftpdlib <= 0.5.1 cpe:2.3:a:g.rodola:pyftpdlib:*:*:*:*:*:*:*:*
g.rodola pyftpdlib 0.1 cpe:2.3:a:g.rodola:pyftpdlib:0.1:*:*:*:*:*:*:*
g.rodola pyftpdlib 0.1.1 cpe:2.3:a:g.rodola:pyftpdlib:0.1.1:*:*:*:*:*:*:*
g.rodola pyftpdlib 0.2.0 cpe:2.3:a:g.rodola:pyftpdlib:0.2.0:*:*:*:*:*:*:*
g.rodola pyftpdlib 0.3.0 cpe:2.3:a:g.rodola:pyftpdlib:0.3.0:*:*:*:*:*:*:*
g.rodola pyftpdlib 0.4.0 cpe:2.3:a:g.rodola:pyftpdlib:0.4.0:*:*:*:*:*:*:*
g.rodola pyftpdlib 0.5.0 cpe:2.3:a:g.rodola:pyftpdlib:0.5.0:*:*:*:*:*:*:*

References for CVE-2009-5011

cvelogic Threat Intelligence