F5 Networks BIG-IP : Python vulnerability (K000159893)

high Nessus Plugin ID 298147

Synopsis

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

Description

The version of F5 Networks BIG-IP installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the K000159893 advisory.

A flaw was found in python. An improperly handled HTTP response in the HTTP client code of python may allow a remote attacker, who controls the HTTP server, to make the client script enter an infinite loop, consuming CPU time. The highest threat from this vulnerability is to system availability.(CVE-2021-3737)

Tenable has extracted the preceding description block directly from the F5 Networks BIG-IP security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

The vendor has acknowledged the vulnerability, but no solution has been provided.
Refer to the vendor for remediation guidance.

See Also

https://my.f5.com/manage/s/article/K000159893

Plugin Details

Severity: High

ID: 298147

File Name: f5_bigip_SOL000159893.nasl

Version: 1.1

Type: local

Published: 2/5/2026

Updated: 2/5/2026

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: High

Base Score: 7.1

Temporal Score: 5.6

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2021-3737

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

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

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:f5:big-ip_irules_lx, cpe:/h:f5:big-ip_protocol_security_manager, cpe:/a:f5:big-ip_domain_name_system, cpe:/a:f5:big-ip_ssl_orchestrator, cpe:/a:f5:big-ip_policy_enforcement_manager, cpe:/a:f5:big-ip_wan_optimization_manager, cpe:/h:f5:big-ip, cpe:/a:f5:big-ip_iapps_lx, cpe:/a:f5:big-ip_advanced_firewall_manager, cpe:/a:f5:big-ip_local_traffic_manager, cpe:/a:f5:big-ip_access_policy_manager, cpe:/a:f5:big-ip_global_traffic_manager, cpe:/a:f5:big-ip_application_security_manager

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

Exploit Available: true

Exploit Ease: Exploits are available

Vulnerability Publication Date: 9/20/2021

Reference Information

CVE: CVE-2021-3737