What’s Vulnerable › Vulnerabilities

CVE-2020-27648

• Severity: critical (CVSS 9.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-10-29 · updated 2026-06-17
• Weakness: CWE-295

Description

Improper certificate validation vulnerability in OpenVPN client in Synology DiskStation Manager (DSM) before 6.2.3-25426-2 allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.

Affected products

• Synology DiskStation Manager: from 6.2 before 6.2.3-25426-2 — fixed in 6.2.3-25426-2
• Synology Skynas Firmware: before 6.2.3-25426 — fixed in 6.2.3-25426

How to fix

Upgrade to a fixed version: Synology DiskStation Manager 6.2.3-25426-2; Synology Skynas Firmware 6.2.3-25426. Check the vendor advisory for mitigations.

References

• https://www.synology.com/security/advisory/Synology_SA_20_18
• https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1058
• https://www.synology.com/security/advisory/Synology_SA_20_18
• https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1058

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