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 accept function having an unexpected value of None for the address, or an ECONNABORTED, EAGAIN, or EWOULDBLOCK error, a related issue to CVE-2010-3492.

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.

ftpserver.py in pyftpdlib before 0.5.2 does not require the l permission for the MLST command, which allows remote authenticated users to bypass intended access restrictions and list the root directory via an FTP session.

Memory leak in the ondtpclose 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.