A malicious backdoor was embedded in the official ProFTPD 1.3.3c source tarball distributed between November 28 and December 2, 2010. The backdoor implements a hidden FTP command trigger that, when invoked, causes the server to execute arbitrary shell commands with root privileges. This allows remote, unauthenticated attackers to run any OS command on the FTP server host.
https://www.vulncheck.com/advisories/proftpd-backdoor-command-execution
https://www.exploit-db.com/exploits/16921
https://www.exploit-db.com/exploits/15662
https://web.archive.org/web/20111107212129/http://rsync.proftpd.org/
https://github.com/proftpd/proftpd
https://advisories.checkpoint.com/defense/advisories/public/2011/cpai-2010-151.html/
Published: 2025-08-20
Updated: 2025-08-22
Base Score: 10
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C
Severity: Critical
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 9.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Severity: Critical
EPSS: 0.0016