Cyber Resilience

CVE-2021-23011

HighDDoS

Published: 10 May 2021

Published
10 May 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0065 71.2th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-23011 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in F5 Big-Ip Access Policy Manager. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 28.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

On versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.3, 14.1.x before 14.1.4, 13.1.x before 13.1.4, 12.1.x before 12.1.6, and 11.6.x before 11.6.5.3, when the BIG-IP system is buffering packet fragments for reassembly, the Traffic Management Microkernel (TMM) may consume an excessive…

more

amount of resources, eventually leading to a restart and failover event. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

f5
big-ip access policy manager
11.6.1 — 11.6.5.3 · 12.1.0 — 12.1.6 · 13.1.0 — 13.1.4
f5
big-ip advanced firewall manager
11.6.1 — 11.6.5.3 · 12.1.0 — 12.1.6 · 13.1.0 — 13.1.4
f5
big-ip advanced web application firewall
11.6.1 — 11.6.5.3 · 12.1.0 — 12.1.6 · 13.1.0 — 13.1.4
f5
big-ip analytics
11.6.1 — 11.6.5.3 · 12.1.0 — 12.1.6 · 13.1.0 — 13.1.4
f5
big-ip application acceleration manager
11.6.1 — 11.6.5.3 · 12.1.0 — 12.1.6 · 13.1.0 — 13.1.4
f5
big-ip application security manager
11.6.1 — 11.6.5.3 · 12.1.0 — 12.1.6 · 13.1.0 — 13.1.4
f5
big-ip ddos hybrid defender
11.6.1 — 11.6.5.3 · 12.1.0 — 12.1.6 · 13.1.0 — 13.1.4
f5
big-ip domain name system
11.6.1 — 11.6.5.3 · 12.1.0 — 12.1.6 · 13.1.0 — 13.1.4
f5
big-ip fraud protection service
11.6.1 — 11.6.5.3 · 12.1.0 — 12.1.6 · 13.1.0 — 13.1.4
f5
big-ip global traffic manager
11.6.1 — 11.6.5.3 · 12.1.0 — 12.1.6 · 13.1.0 — 13.1.4
+4 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-400

Limiting concurrent sessions directly prevents uncontrolled resource consumption by capping the number of active sessions per user or account.

addresses: CWE-400

Analysis identifies uncontrolled resource consumption indicative of denial-of-service or abuse attempts.

addresses: CWE-400

Contingency plan testing includes resource exhaustion scenarios to verify recovery, making it harder for attackers to sustain exploits that cause uncontrolled consumption.

addresses: CWE-400

Updated contingency plans include current procedures to detect, contain, and recover from resource exhaustion, limiting an attacker's ability to sustain impact from uncontrolled consumption.

addresses: CWE-400

Alternate site allows resumption of operations if resource exhaustion at the primary site is exploited to cause unavailability.

addresses: CWE-400

Alternate telecommunications services enable resumption of essential functions when primary services become unavailable due to uncontrolled resource consumption.

addresses: CWE-400

The team can analyze and respond to resource exhaustion incidents, reducing the impact of attacks that exploit uncontrolled consumption weaknesses.

addresses: CWE-400

Timely maintenance support and spare parts enable rapid recovery from failures induced by uncontrolled resource consumption, shortening the impact window of denial-of-service attacks.

References