Core FTP 2.0 build 653 contains a denial of service vulnerability in the PBSZ command that allows unauthenticated attackers to crash the service by sending a malformed command with an oversized buffer. Attackers can send a PBSZ command with a payload exceeding 211 bytes to trigger an access violation and crash the FTP server process.

Core FTP/SFTP Server 1.2 contains a buffer overflow vulnerability that allows attackers to crash the service by supplying an excessively long string in the User domain field. Attackers can paste a malicious payload containing 7000 bytes of data into the domain configuration to trigger an application crash and deny service.