CVE-2021-23000

mediumpriority · track · 30EPSS 0.010 · 62 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.97% (62nd) EPSS

CVSS 4.3 · medium

Is it mine?

29 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-27

On BIG-IP versions 13.1.3.4-13.1.3.6 and 12.1.5.2, if the tmm.http.rfc.enforcement BigDB key is enabled in a BIG-IP system, or the Bad host header value is checked in the AFM HTTP security profile associated with a virtual server, in rare instances, a specific sequence of malicious requests may cause TMM to restart. Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.3–7.5

v2.04.3mediumAV:N/AC:M/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-400USLLM-inferredCWE-476USLLM-inferred

affected products (29)

Products and version ranges known to be affected.

n/a BIG-IP≤ 13.1.3.4-13.1.3.5, 12.1.5.2enisa_euvdEU
f5 big-ip access policy manager= 12.1.5.2nvdUScpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip access policy manager13.1.3.4 → 13.1.3.6nvdUScpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip advanced firewall manager= 12.1.5.2nvdUScpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 big-ip advanced firewall manager13.1.3.4 → 13.1.3.6nvdUScpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 big-ip advanced web application firewall= 12.1.5.2nvdUScpe:2.3:a:f5:big-ip_advanced_web_application_firewall:*:*:*:*:*:*:*:*
f5 big-ip advanced web application firewall13.1.3.4 → 13.1.3.6nvdUScpe:2.3:a:f5:big-ip_advanced_web_application_firewall:*:*:*:*:*:*:*:*
f5 big-ip analytics= 12.1.5.2nvdUScpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
f5 big-ip analytics13.1.3.4 → 13.1.3.6nvdUScpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
f5 big-ip application acceleration manager= 12.1.5.2nvdUScpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
f5 big-ip application acceleration manager13.1.3.4 → 13.1.3.6nvdUScpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
f5 big-ip application security manager= 12.1.5.2nvdUScpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 big-ip application security manager13.1.3.4 → 13.1.3.6nvdUScpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 big-ip ddos hybrid defender= 12.1.5.2nvdUScpe:2.3:a:f5:big-ip_ddos_hybrid_defender:*:*:*:*:*:*:*:*
f5 big-ip ddos hybrid defender13.1.3.4 → 13.1.3.6nvdUScpe:2.3:a:f5:big-ip_ddos_hybrid_defender:*:*:*:*:*:*:*:*
f5 big-ip domain name system= 12.1.5.2nvdUScpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 big-ip domain name system13.1.3.4 → 13.1.3.6nvdUScpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 big-ip fraud protection service= 12.1.5.2nvdUScpe:2.3:a:f5:big-ip_fraud_protection_service:*:*:*:*:*:*:*:*
f5 big-ip fraud protection service13.1.3.4 → 13.1.3.6nvdUScpe:2.3:a:f5:big-ip_fraud_protection_service:*:*:*:*:*:*:*:*
f5 big-ip global traffic manager= 12.1.5.2nvdUScpe:2.3:a:f5:big-ip_global_traffic_manager:*:*:*:*:*:*:*:*

showing 20 of 29

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2021-03-31modified 2026-06-17

references (6)

External citations — patches, advisories, analysis.

scry

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