{"id":"CVE-2009-5011","aliases":["GHSA-62xg-239j-vxg7","PYSEC-2010-8"],"url":"https://o3.security/vulnerability/CVE-2009-5011","summary":"Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') in pyftpdlib","details":"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":"2010-10-19T20:00:03Z","modified":"2026-04-10T03:41:02.944411Z","cvss":null,"epss":{"score":0.00916,"percentile":0.57514,"asOf":"2026-08-22"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"pyftpdlib","fixedVersion":"0.5.2"}],"fix":null,"references":[{"type":"WEB","url":"http://code.google.com/p/pyftpdlib/issues/detail?id=100"},{"type":"WEB","url":"http://code.google.com/p/pyftpdlib/source/browse/trunk/HISTORY"},{"type":"WEB","url":"http://code.google.com/p/pyftpdlib/source/detail?r=543"},{"type":"WEB","url":"http://code.google.com/p/pyftpdlib/source/diff?spec=svn543&r=543&format=side&path=/trunk/pyftpdlib/ftpserver.py"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2009-5011"},{"type":"PACKAGE","url":"https://github.com/giampaolo/pyftpdlib"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/pyftpdlib/PYSEC-2010-8.yaml"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-04-10T03:41:02.944411Z"}}