What is CVE-2017-18421?

CVE-2017-18421 is a low-severity vulnerability in Cpanel, classified under Improper Access Control. CVSS score: 3.3/10. Published 2019-08-02.

How severe is CVE-2017-18421?

Low severity. CVSS v3 base score is 3.3 out of 10.

Vulnerability in Cpanel

CVE-2017-18421

cPanel before 66.0.2 allows demo accounts to create databases and users (SEC-271).

Published 2019-08-02 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 3.3 (Low). Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (23.0th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Cpanel

Weakness classification (CWE)

CWE-284 — Improper Access Control

References

documentation.cpanel.net/display/CL/66+Change+Log (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2017-18421?: CVE-2017-18421 is a low-severity vulnerability in Cpanel, classified under Improper Access Control. CVSS score: 3.3/10. Published 2019-08-02.
How severe is CVE-2017-18421?: Low severity. CVSS v3 base score is 3.3 out of 10.