Race condition in the FTPHandler class in ftpserver.py in pyftpdlib before 0.5.1 allows remote attackers to cause a denial of service (daemon outage) by establishing and then immediately closing a TCP connection, leading to the accept function having an unexpected return value of None, a different vulnerability than CVE-2010-3494.

References

• https://nvd.nist.gov/vuln/detail/CVE-2009-5010
• https://bugs.launchpad.net/zodb/+bug/135108
• http://bugs.python.org/issue6706
• http://code.google.com/p/pyftpdlib/issues/detail?id=91
• http://www.openwall.com/lists/oss-security/2010/09/09/6
• http://www.openwall.com/lists/oss-security/2010/09/11/2
• http://www.openwall.com/lists/oss-security/2010/09/22/3
• http://www.openwall.com/lists/oss-security/2010/09/24/3
• GHSA-mpg6-rgp4-35rr
• https://github.com/pypa/advisory-database/tree/main/vulns/pyftpdlib/PYSEC-2010-7.yaml
• http://code.google.com/p/pyftpdlib/source/browse/trunk/HISTORY
• http://code.google.com/p/pyftpdlib/source/detail?r=439
• http://code.google.com/p/pyftpdlib/source/diff?spec=svn439&r=439&format=side&path=/trunk/pyftpdlib/ftpserver.py