CVE-2021-3773
kernel: lack of port sanity checking in natd and netfilter leads to exploit of OpenVPN clients
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · September 8, 2021
Updated · June 28, 2026
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 score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options does not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor