CVE-2021-47961

Name: CVE-2021-47961
Creator: NVD / NIST
Published: 2026-04-10T10:16:03.913+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.1/10EPSS 0.32%

Last modified Jun 17, 2026

CVE-2021-47961 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. A plaintext storage of a password vulnerability in Synology SSL VPN Client before 1.4.5-0684 allows remote attackers to access or influence the user's PIN code due to insecure storage. This may lead to unauthorized VPN configuration and potential interception of subsequent VPN traffic when combined with user interaction.. EPSS estimates a 0.32% chance of exploitation in the next 30 days.

Description

A plaintext storage of a password vulnerability in Synology SSL VPN Client before 1.4.5-0684 allows remote attackers to access or influence the user's PIN code due to insecure storage. This may lead to unauthorized VPN configuration and potential interception of subsequent VPN traffic when combined with user interaction.

Metrics

CVSS 3.1

8.1/10

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

EPSS Probability

0.32%

24.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-256

Affected Software

Vendor	Product	Versions
Synology	Ssl Vpn Client	< 1.4.5-0684

References

https://www.synology.com/en-global/security/advisory/Synology_SA_26_05Vendor Advisory

Timeline

Published: Apr 10, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-47961?

How severe is CVE-2021-47961?

CVE-2021-47961 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 0.32% probability of exploitation in the next 30 days.

How do I fix CVE-2021-47961?

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-2021-47961?

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

Scan your code now

Source: NVD / NIST