What’s Vulnerable › Vulnerabilities

CVE-2021-27891

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-03-15 · updated 2026-06-17

Description

SSH Tectia Client and Server before 6.4.19 on Windows have weak key generation. ConnectSecure on Windows is affected.

Affected products

• SSH Tectia Client: before 6.4.19 — fixed in 6.4.19
• SSH Tectia Connectsecure: all versions
• SSH Tectia Server: before 6.4.19 — fixed in 6.4.19

How to fix

Upgrade to a fixed version: SSH Tectia Client 6.4.19; SSH Tectia Server 6.4.19. Check the vendor advisory for mitigations.

References

• https://info.ssh.com/tectia-vulnerability-cve-2021-27891
• https://info.ssh.com/tectia-vulnerability-cve-2021-27891

Get alerted when CVE-2021-27891 or the next vulnerability affects your stack