CVE-2021-3547: openvpn
CVSS: 7.4v3.1HighModified
Published 12-07-2021Last modified 03-08-2024
Vulnerability summary
CVE-2021-3547 is a high (CVSS 7.4) vulnerability in openvpn. EPSS estimates a 1.24% chance of exploitation in the next 30 days, higher than 68.7% of scored vulnerabilities.
CVSS score
7.4/10
010
High · v3.1 (NVD)EPSS score
1.24%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 12-07-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
2 scores · 1 source · 2 versionsHigh 7.4Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NSourcesSingle source
Medium 5.8Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:P/I:P/A:NSourcesSingle source
EPSS trend
Probability
1.24%
Chance of exploitation in the next 30 days
Percentile
69%
Versus all other CVEs
30-day change
0.00 pp
From 1.24% on 20-09-2026
20-09-202620-10-2026
EPSS score1.24%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-305Authentication Bypass by Primary WeaknessThe authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error.
- CWE-295Improper Certificate ValidationThe product does not validate, or incorrectly validates, a certificate.
Affected systems
Openvpn1 product
- openvpn3.6 | 3.6.1
1 vendor · 1 product