What steps will reproduce the problem?  
1. start pyftpdlib
2. after login the server, move into a deep directory
3. send a CDUP command

192.168.3.3:4117 <== CWD /abc/def
192.168.3.3:4117 ==> 250 "/abc/def" is the current directory.
192.168.3.3:4117 <== CDUP
192.168.3.3:4117 ==> 250 "/" is the current directory. 

What is the expected output?  


What do you see instead?  
192.168.3.3:4117 ==> 250 "/abc" is the current directory. What version of 
pyftpdlib are you using? On what operating system? Which Python version? 
ftpserver r609 Windows vista
CPython 2.6.2 

Please provide any additional information below.  
When you send a CDUP command,
FTPHandler.found_terminator method finds the real parent directory in line
1844.
But ftp_CDUP method calls ftp_CWD method with a hard-coded path in line 2735. 

I think ftp_CDUP should call ftp_CWD like this:
self.ftp_CWD(line)