CVE-2021-47865

HIGH 7.5

ProFTPD 1.3.7a - Remote Denial of Service

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-770
Vendor	proftpd
Product	proftpd
Published	Jan 21, 2026
Last Updated	Apr 7, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

ProFTPD / ProFTPD

1.3.7a

References

NVD ↗ CVE.org ↗ EPSS Data ↗

exploit-db.com: https://www.exploit-db.com/exploits/49697 proftpd.org: http://www.proftpd.org/ github.com: https://github.com/proftpd/proftpd/issues/1298 vulncheck.com: https://www.vulncheck.com/advisories/proftpd-a-remote-denial-of-service

Credits

xynmaps