CVE-2021-36809

Name: CVE-2021-36809
Creator: NVD / NIST
Published: 2022-03-08T00:15:07.717+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6/10EPSS 0.22%

Last modified Jun 17, 2026

CVE-2021-36809 is a medium-severity vulnerability rated 6/10 on the CVSS scale. A local attacker can overwrite arbitrary files on the system with VPN client logs using administrator privileges, potentially resulting in a denial of service and data loss, in all versions of Sophos SSL VPN client.. EPSS estimates a 0.22% chance of exploitation in the next 30 days.

Description

A local attacker can overwrite arbitrary files on the system with VPN client logs using administrator privileges, potentially resulting in a denial of service and data loss, in all versions of Sophos SSL VPN client.

Metrics

CVSS 3.1

6/10

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

EPSS Probability

0.22%

12.6th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Sophos	Ssl Vpn Client	All versions

References

https://www.sophos.com/en-us/security-advisories/sophos-sa-20220303-sslvpn-local-dosVendor Advisory
https://www.sophos.com/en-us/security-advisories/sophos-sa-20220303-sslvpn-local-dosVendor Advisory

Timeline

Published: Mar 8, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-36809?

How severe is CVE-2021-36809?

CVE-2021-36809 has a CVSS score of 6/10 (MEDIUM severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.

How do I fix CVE-2021-36809?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-36809?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST