Cyber Resilience

CVE-2024-21771

DoS in F5 Big-Ip Advanced Firewall Manager 15.1.0 – 15.1.9

DoS
Published
14 February 2024
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0052 41th percentile
Risk Priority 58 floored blend · peak EPSS

Summary

CVE-2024-21771 is a high-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in F5 Big-Ip Advanced Firewall Manager. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Network Denial of Service (T1498); ranked at the 41th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-10 (Concurrent Session Control) and SC-6 (Resource Availability) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

For unspecified traffic patterns, BIG-IP AFM IPS engine may spend an excessive amount of time matching the traffic against signatures, resulting in Traffic Management Microkernel (TMM) restarting and traffic disruption. Note: Software versions which have reached End of Technical Support…

more

(EoTS) are not evaluated

CWE(s)
CWE-770

Related Threats

MITRE ATT&CK Enterprise Techniques

T1498 Network Denial of Service Impact
Adversaries may perform Network Denial of Service (DoS) attacks to degrade or block the availability of targeted resources to users.
attack.mitre.org →
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
attack.mitre.org →
T1498.001 Direct Network Flood Impact
Adversaries may attempt to cause a denial of service (DoS) by directly sending a high-volume of network traffic to a target.
attack.mitre.org →
T1498.002 Reflection Amplification Impact
Adversaries may attempt to cause a denial of service (DoS) by reflecting a high-volume of network traffic to a target.
attack.mitre.org →
T1499.001 OS Exhaustion Flood Impact
Adversaries may launch a denial of service (DoS) attack targeting an endpoint's operating system (OS).
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-24312Same product: F5 Big-Ip Advanced Firewall Manager
CVE-2024-23979Same product: F5 Big-Ip Advanced Firewall Manager
CVE-2023-22323Same product: F5 Big-Ip Advanced Firewall Manager
CVE-2024-21763Same product: F5 Big-Ip Advanced Firewall Manager
CVE-2023-40542Same product: F5 Big-Ip Advanced Firewall Manager
CVE-2026-40423Same product: F5 Big-Ip Advanced Firewall Manager
CVE-2025-46706Same product: F5 Big-Ip Advanced Firewall Manager
CVE-2025-36504Same product: F5 Big-Ip Advanced Firewall Manager
CVE-2026-40629Same product: F5 Big-Ip Advanced Firewall Manager
CVE-2025-54500Same product: F5 Big-Ip Advanced Firewall Manager

Affected Assets

f5
big-ip advanced firewall manager
17.1.0 · 15.1.0 — 15.1.9 · 16.1.0 — 16.1.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V15.4.4

Mitigating Controls (NIST 800-53 r5) AI

AC-10 Concurrent Session Control good match

Directly enforces a hard limit on concurrent sessions, structurally preventing unbounded resource allocation.

SC-6 Resource Availability good match

Requires explicit allocation of resources by priority or quota, directly stopping unlimited allocation.

AC-7 Unsuccessful Logon Attempts partial match

Imposes a limit on consecutive invalid attempts, preventing one specific class of unbounded resource consumption.

SC-5 Denial-of-service Protection partial match

Reduces impact of resulting DoS events without preventing the underlying lack of allocation limits.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.IR-04 mostly match
degrades

Monitoring capacity and taking action to maintain availability directly reduces unchecked resource allocation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.16 Monitoring activities mostly match
finds

Baseline comparison of CPU, memory and bandwidth usage helps surface uncontrolled resource allocations before they cause service degradation.

A.8.6 Capacity management mostly match
prevents

Capacity projections and elasticity measures ensure that allocation requests are bounded and can be throttled, reducing the window in which an attacker can force unbounded resource reservations.

A.8.13 Information backup partial match
mitigates

Defining retention periods and deletion schedules for backup copies prevents indefinite accumulation of data on storage media without corresponding resource-management controls.

A.8.14 Redundancy of information processing facilities partial match
mitigates

Architectural redundancy and automatic failover limit the impact of an attacker who forces excessive allocations, because spare capacity can absorb the load until the primary instance recovers.

A.5.24 Information security incident management planning and preparation none match
none

Documented incident response procedures that include activation of continuity plans and controlled recovery help ensure that resource consumption triggered by an incident is bounded and managed rather than left unbounded.

A.5.29 Information security during disruption none match
mitigates

Mandating tested continuity procedures that preserve or replace resource-limiting controls prevents an attacker from exploiting the absence of throttling mechanisms during an outage.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248552 OL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770
  • V-248553 OL 8 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-770
Oracle Linux 9 (2 rules)
  • V-271710 OL 9 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-770
  • V-271709 OL 9 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770
RHEL 8 (1 rule)
  • V-230244 RHEL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770

References