FTPShell Server 6.83 contains a buffer overflow vulnerability that allows local attackers to crash the application by supplying an excessively long string in the account name field. Attackers can trigger a denial of service by pasting a 417-byte payload into the 'Account name to ban' parameter within the Manage FTP Accounts interface.
Stack-based buffer overflow in FTPShell Server 4.3 allows user-assisted remote attackers to cause a denial of service (persistent daemon crash) and possibly execute arbitrary code via a long string in a licensing key (aka .key) file.
FTPshell Server 3.38 allows remote authenticated users to cause a denial of service (application crash) by multiple connections and disconnections without using the QUIT command.