psftp PSFTPd 10.0.4

A use-after-free issue could be triggered remotely in the SFTP component of PSFTPd 10.0.4 Build 729. This issue could be triggered prior to authentication. The PSFTPd server did not automatically restart, which enabled attackers to perform a very effective DoS attack against this service. By sending a crafted SSH identification / version string to the server, a NULL pointer dereference could be caused, apparently because of a race condition in the window message handling, performing the cleanup for invalid connections. This incorrect cleanup code has a use-after-free.

The PSFTPd 10.0.4 Build 729 server does not properly escape data before writing it into a Comma Separated Values (CSV) file. This can be used by attackers to hide data in the Graphical User Interface (GUI) view and create arbitrary entries to a certain extent. Special characters such as '"' and ',' and '\r' are not escaped and can be used to add new entries to the log.

The PSFTPd 10.0.4 Build 729 server stores its configuration inside PSFTPd.dat. This file is a Microsoft Access Database and can be extracted. The application sets the encrypt flag with the password "ITsILLEGAL"; however, this password is not required to extract the data. Cleartext is used for a user password.

The PSFTPd 10.0.4 Build 729 server does not prevent FTP bounce scans by default. These can be performed using "nmap -b" and allow performing scans via the FTP server.