7.4
HIGH
CVE-2021-3547
OpenVPN Cert Authentication Bypass
Description

OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.

INFO

Published Date :

July 12, 2021, 11:15 a.m.

Last Modified :

Oct. 27, 2022, 12:22 p.m.

Remotely Exploitable :

Yes !

Impact Score :

5.2

Exploitability Score :

2.2
Affected Products

The following products are affected by CVE-2021-3547 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Openvpn openvpn
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-3547.

URL Resource
https://community.openvpn.net/openvpn/wiki/CVE-2021-3547 Patch Vendor Advisory
https://community.openvpn.net/openvpn/wiki/SecurityAnnouncements Vendor Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-3547 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-3547 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Reanalysis by [email protected]

    Oct. 27, 2022

    Action Type Old Value New Value
    Removed CWE NIST CWE-287
    Added CWE NIST CWE-295
  • Initial Analysis by [email protected]

    Jul. 15, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:M/Au:N/C:P/I:P/A:N)
    Added CVSS V3.1 NIST AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
    Changed Reference Type https://community.openvpn.net/openvpn/wiki/CVE-2021-3547 No Types Assigned https://community.openvpn.net/openvpn/wiki/CVE-2021-3547 Patch, Vendor Advisory
    Changed Reference Type https://community.openvpn.net/openvpn/wiki/SecurityAnnouncements No Types Assigned https://community.openvpn.net/openvpn/wiki/SecurityAnnouncements Vendor Advisory
    Added CWE NIST CWE-287
    Added CPE Configuration OR *cpe:2.3:a:openvpn:openvpn:3.6:*:*:*:*:*:*:* *cpe:2.3:a:openvpn:openvpn:3.6.1:*:*:*:*:*:*:*
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-3547 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-3547 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.09 }} -0.00%

score

0.35541

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
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Scope
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