Unprotected storage of credentials in SSL VPN Client - CVE-2021-47961
Published: April 14, 2026
Vulnerability identifier: #VU125952
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2021-47961
CWE-ID: CWE-256
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Synology Inc.
Affected software:
SSL VPN Client
SSL VPN Client
Detailed vulnerability description
The vulnerability allows a remote attacker to obtain or manipulate the PIN code, potentially leading to unauthorized VPN configuration and traffic interception.
The vulnerability exists due to plaintext storage of a password in PIN code storage when a user interacts with a crafted web page. A remote attacker can trick the victim into interacting with a crafted web page to obtain or manipulate the PIN code, potentially leading to unauthorized VPN configuration and traffic interception.
User interaction is required.
How to mitigate CVE-2021-47961
Install security update from vendor's website.