What’s Vulnerable › Vulnerabilities

CVE-2020-27633

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-10-10 · updated 2026-06-17
• Weakness: CWE-330

Description

In FNET 4.6.3, TCP ISNs are improperly random.

Affected products

• Butok Fnet: 4.6.3

References

• https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01
• https://www.forescout.com
• https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/
• https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01
• https://www.forescout.com
• https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/

Get alerted when CVE-2020-27633 or the next vulnerability affects your stack