8.7

CVE-2021-47865: proftpd

CVSS: 8.7v4.0HighDeferred
AliasesUBUNTU-CVE-2021-47865
Published 21-01-2026Last modified 07-04-2026
Open JSON

Vulnerability summary

CVE-2021-47865 is a high (CVSS 8.7) vulnerability in proftpd. EPSS estimates a 0.60% chance of exploitation in the next 30 days, higher than 47.5% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
45/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.7/10
010
High · v4.0 (CVE.org)
EPSS score
0.60%
0%100%
Low · -0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1exploit-database

Timeline

  1. 21-01-2026
    PublishedVulnerability first disclosed.
  2. 07-04-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

6 scores · 3 sources · 2 versions

EPSS trend

Probability

0.60%

Chance of exploitation in the next 30 days

Percentile

48%

Versus all other CVEs

30-day change

-0.01 pp

From 0.61% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.60%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • exploit-databasedosmultipleUnverified

    ProFTPD 1.3.7a - Remote Denial of Service

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Proftpd1 product
Ubuntu1 product
  • proftpd-dfsgAll versions (No fix recorded)

2 vendors · 2 products

References

7 links