CVE-2021-47865: ProFTPD

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

ProFTPD 1.3.7a contains a denial of service vulnerability that allows attackers to overwhelm the server by creating multiple simultaneous FTP connections. Attackers can repeatedly establish connections using threading to exhaust server connection limits and block legitimate user access.

Affected products

• ProFTPD ProFTPD: version 1.3.7a only

Published 2026-01-21. Last modified 2026-06-17.