ProFTPD 1.2.7 through 1.2.9rc2 does not properly translate newline characters when transferring files in ASCII mode, which allows remote attackers to execute arbitrary code via a buffer overflow using certain files.

ProFTPD 1.3.3c Backdoor Command Execution

A malicious backdoor was embedded in the official ProFTPD 1.3.3c source tarball distributed between November 28 and December 2, 2010. The backdoor implements a hidden FTP command trigger that, when invoked, causes the server to execute arbitrary shell commands with root privileges. This allows remote, unauthenticated attackers to run any OS command on the FTP server host.