F5 Networks BIG-IP : BIG-IP virtual server TCP sequence numbers vulnerability (K64571774)

Medium Nessus Plugin ID 143103

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VPR Score: 3.8


The remote device is missing a vendor-supplied security patch.


On specific BIG-IP platforms, attackersmay 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.(CVE-2020-5947)


Attackersmay be able to spoof TCP packets to be used by a future connection, resulting in a TCP sequence prediction attack.

The following BIG-IP platforms do not contain the high speed bus (HSBe2) chip and do not have hardware-based SYN cookie capability, and are therefore vulnerable :

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)


Upgrade to one of the non-vulnerable versions listed in the F5 Solution K64571774.

See Also


Plugin Details

Severity: Medium

ID: 143103

File Name: f5_bigip_SOL64571774.nasl

Version: 1.1

Type: local

Published: 2020/11/19

Updated: 2020/11/19

Dependencies: 76940

Configuration: Enable paranoid mode

Risk Information

Risk Factor: Medium

VPR Score: 3.8

CVSS v2.0

Base Score: 6.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P

CVSS v3.0

Base Score: 6.3

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Vulnerability Information

CPE: cpe:/a:f5:big-ip_access_policy_manager, cpe:/a:f5:big-ip_advanced_firewall_manager, cpe:/a:f5:big-ip_application_acceleration_manager, cpe:/a:f5:big-ip_application_security_manager, cpe:/a:f5:big-ip_application_visibility_and_reporting, cpe:/a:f5:big-ip_global_traffic_manager, cpe:/a:f5:big-ip_link_controller, cpe:/a:f5:big-ip_local_traffic_manager, cpe:/a:f5:big-ip_policy_enforcement_manager, cpe:/h:f5:big-ip

Required KB Items: Host/local_checks_enabled, Host/BIG-IP/hotfix, Host/BIG-IP/modules, Host/BIG-IP/version, Settings/ParanoidReport

Patch Publication Date: 2020/11/18

Reference Information

CVE: CVE-2020-5947