High severity · published Apr 10, 2026
CVE-2021-47961
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…
8.1
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SS
Synology SSL VPN Client · Synology
before 1.4.5-0684 · source: vendor
SV
Ssl Vpn Client · Synology
before 1.4.5-0684 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-47961
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-47961
Vendor Advisory
https://www.synology.com/en-global/security/advisory/Synology_SA_26_05
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6.5
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A files or directories accessible to external parties vulnerability in Synology SSL VPN Client before 1.4.5-0684 allows remote attackers to access files within the installation…