What is CVE-2021-39602?

CVE-2021-39602 is a medium-severity vulnerability in Miniftpd Project, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 6.5/10. Published 2021-08-23.

How severe is CVE-2021-39602?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Buffer overflow in Miniftpd Project

CVE-2021-39602

A Buffer Overflow vulnerabilty exists in Miniftpd 1.0 in the do_mkd function in the ftpproto.c file, which could let a remote malicious user cause a Denial of Service.

Vulnerability class: Buffer Overflow

Published 2021-08-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.008 (56.5th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Miniftpd Project — versions 1.0

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

github.com/Gabe-commiter/Miniftpd/issues/1 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2021-39602?: CVE-2021-39602 is a medium-severity vulnerability in Miniftpd Project, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 6.5/10. Published 2021-08-23.
How severe is CVE-2021-39602?: Medium severity. CVSS v3 base score is 6.5 out of 10.