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Vulnerability record · CVE-2021-3824 · published 23 September 2021

CVE-2021-3824: Openvpn access server cross-site scripting vulnerability

Openvpn · Openvpn Access Server

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.

6.1 CVSS 3.1 Medium EPSS 0.75% · top 47.0% CWE-84 · CWE-84CWE-79 · Cross-site scripting
6.1CVSS 3.1 base score, v2 4.3
0.75%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://openvpn.net/vpn-server-resources/release-notes/#openvpn-access-server-2-9-5 Release NotesVendor Advisory
https://openvpn.net/vpn-server-resources/release-notes/#openvpn-access-server-2-9-5 Release NotesVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2023-46850Openvpn use after free vulnerabilityUse after free in OpenVPN version 2.6.0 to 2.6.6 may lead to undefined behavoir, leaking memory buffers or remote execution when sending network buff…EPSS 2.0%9.8CVE-2020-8953Openvpn access server improper authentication vulnerabilityOpenVPN Access Server 2.8.x before 2.8.1 allows LDAP authentication bypass (except when a user is enrolled in two-factor authentication).EPSS 1.3%9.0CVE-2006-1629Openvpn vulnerabilityOpenVPN 2.0 through 2.0.5 allows remote malicious servers to execute arbitrary code on the client by using setenv with the LD_PRELOAD environment var…EPSS 3.1%7.5CVE-2023-46849Openvpn divide by zero vulnerabilityUsing the --fragment option in certain configuration setups OpenVPN version 2.6.0 to 2.6.6 allows an attacker to trigger a divide by zero behaviour w…EPSS 1.2%7.5CVE-2021-4234Openvpn access server vulnerabilityOpenVPN Access Server 2.10 and prior versions are susceptible to resending multiple packets in a response to a reset packet sent from the client whic…EPSS 0.89%7.5CVE-2022-33737Openvpn access server sensitive information in log file vulnerabilityThe OpenVPN Access Server installer creates a log file readable for everyone, which from version 2.10.0 and before 2.11.0 may contain a random genera…EPSS 0.87%7.5CVE-2022-33738Openvpn access server vulnerabilityOpenVPN Access Server before 2.11 uses a weak random generator used to create user session token for the web portalEPSS 0.92%7.5CVE-2020-36382Openvpn access server vulnerabilityOpenVPN Access Server 2.7.3 to 2.8.7 allows remote attackers to trigger an assert during the user authentication phase via incorrect authentication t…EPSS 1.9%

Source: NIST National Vulnerability Database (record CVE-2021-3824), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.