[原文]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.
wu-ftpd contains a flaw that may allow a malicious user to gain access to unauthorized privileges. The issue is triggered when an ftp client is transferring a file, then closes the connection and sends an ABOR command, which causes the server to execute the dologout() function, allowing the user to gain root privileges. This flaw may lead to a loss of confidentiality and/or integrity.
Upgrade to version 2.4.2 or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.