wu-ftpd 2.4 FTP server does not properly drop privileges when an ABOR (abort file transfer) command is executed during a file transfer, which causes a signal to be handled incorrectly and allows local and possibly remote attackers to read arbitrary files.
Certain configurations of wu-ftp FTP server 2.4 use a _PATH_EXECPATH setting to a directory with dangerous commands, such as /bin, which allows remote authenticated users to gain root access via the "site exec" command.