What is CVE-2021-3824?

CVE-2021-3824 is a medium-severity vulnerability in Openvpn Access Server, classified under CWE-84. CVSS score: 6.1/10. Published 2021-09-23.

How severe is CVE-2021-3824?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Openvpn Access Server

CVE-2021-3824

OpenVPN Access Server 2.9.0 through 2.9.4 allow remote attackers to inject arbitrary web script or HTML via the web login page URL.

Published 2021-09-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (54.3th percentile), scored 2026-10-23.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 54.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Openvpn Access Server
Openvpn Access Server — versions 2.9.0 through 2.9.4

Weakness classification (CWE)

References

openvpn.net/vpn-server-resources/release-notes/ (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2021-3824?: CVE-2021-3824 is a medium-severity vulnerability in Openvpn Access Server, classified under CWE-84. CVSS score: 6.1/10. Published 2021-09-23.
How severe is CVE-2021-3824?: Medium severity. CVSS v3 base score is 6.1 out of 10.