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Fencer Intel
medium 4.3

CVE-2020-5947 json

In versions 16.0.0-16.0.0.1 and 15.1.0-15.1.1, on specific BIG-IP platforms, attackers may be able to obtain TCP sequence numbers from the…

published 5y ago modified 4mo ago also EUVD-2020-27101

cvss
4.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits
0
none known

Summary

In versions 16.0.0-16.0.0.1 and 15.1.0-15.1.1, on specific BIG-IP platforms, attackers may be able to obtain TCP sequence numbers from the BIG-IP system that can be reused in future connections with the same source and destination port and IP numbers. Only these platforms are affected: BIG-IP 2000 series (C112), BIG-IP 4000 series (C113), BIG-IP i2000 series (C117), BIG-IP i4000 series (C115), BIG-IP Virtual Edition (VE).

Patch / fix

  • f5 big-ip_access_policy_manager 15.1.2, 16.0.1
  • f5 big-ip_advanced_firewall_manager 15.1.2, 16.0.1
  • f5 big-ip_advanced_web_application_firewall 15.1.2, 16.0.1
  • f5 big-ip_analytics 15.1.2, 16.0.1
  • f5 big-ip_application_acceleration_manager 15.1.2, 16.0.1
  • f5 big-ip_application_security_manager 15.1.2, 16.0.1
  • f5 big-ip_ddos_hybrid_defender 15.1.2, 16.0.1
  • f5 big-ip_domain_name_system 15.1.2, 16.0.1
  • f5 big-ip_fraud_protection_service 15.1.2, 16.0.1
  • f5 big-ip_global_traffic_manager 16.0.1
  • f5 big-ip_link_controller 15.1.2, 16.0.1
  • f5 big-ip_local_traffic_manager 15.1.2, 16.0.1
  • f5 big-ip_policy_enforcement_manager 15.1.2, 16.0.1
  • f5 ssl_orchestrator 15.1.2, 16.0.1

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Exploit prediction

0.70% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
NVD 2.0 4.0 AV:N/AC:L/Au:S/C:P/I:N/A:N

Affected products

  • n/a BIG-IP 2000 series (C112), BIG-IP 4000 series (C113), BIG-IP i2000 series (C117), BIG-IP i4000 series (C115), BIG-IP Virtual Edition (VE)

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.