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Vulnerability record · CVE-2021-3773 · published 16 February 2022

CVE-2021-3773: Linux kernel information exposure vulnerability

Linux · Linux Kernel

A flaw in netfilter could allow a network-connected attacker to infer openvpn connection endpoint information for further use in traditional network attacks.

9.8 CVSS 3.1 Critical EPSS 5.3% · top 7.7% CWE-200 · Information exposure
9.8CVSS 3.1 base score, v2 7.5
5.3%EPSS exploitation probability, 30 days
NoNot in CISA KEV
6Affected product versions listed by NVD
7References
17 Jun 2026Last modified by NVD

Description

A flaw in netfilter could allow a network-connected attacker to infer openvpn connection endpoint information for further use in traditional network attacks.

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

Affected products

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

References

LinkTags
https://bugzilla.redhat.com/show_bug.cgi?id=2004949 Issue TrackingThird Party Advisory
https://citizenlab.ca/2024/07/vulnerabilities-in-vpns-paper-presented-at-the-privacy-enhancing-technologies-symposium-20
https://www.oracle.com/security-alerts/cpujul2022.html PatchThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2004949 Issue TrackingThird Party Advisory
https://citizenlab.ca/2024/07/vulnerabilities-in-vpns-paper-presented-at-the-privacy-enhancing-technologies-symposium-20
https://security.netapp.com/advisory/ntap-20250328-0004/
https://www.oracle.com/security-alerts/cpujul2022.html PatchThird Party Advisory

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

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Source: NIST National Vulnerability Database (record CVE-2021-3773), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.