FTPShell Server 6.83 incorporates a buffer overflow that can be triggered by entering a 417‑byte string in the 'Account name to ban' field of the Manage FTP Accounts interface. The overflow resides in the account name handling code and causes the application to crash, resulting in a denial of service. This weakness is represented by CWE‑787, indicating a memory overwrite that compromises application stability.

The affected product is FTPShell Server, distributed by Ftpshell, with version 6.83 specifically listed in the CVE data. The CPE strings also reference a 2002 release, but no explicit vulnerability is documented for that version. No other affected versions are identified in the provided information.

The CVSS score of 6.9 classifies the vulnerability as medium‑to‑high severity for a denial of service. EPSS data is unavailable, and the issue is not listed in CISA’s KEV catalog, suggesting no widely known exploitation. The attack requires local access and the ability to use the Manage FTP Accounts interface; a privileged local user can paste the overlong payload to crash the service, causing an outage. No additional exploitation conditions are mentioned.