Cyber Resilience

CVE-2025-21091

F5 Big-Ip Access Policy Manager 15.1.0 – 15.1.10

Published
05 February 2025
Modified
21 October 2025
Patch / advisory
CVSS Score v4 8.7
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0044 37th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2025-21091 is a high-severity Missing Release of Memory after Effective Lifetime (CWE-401) vulnerability in F5 Big-Ip Access Policy Manager. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 37th 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 SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-21091 affects F5 BIG-IP systems when SNMP v1 or v2c are disabled, allowing undisclosed requests to cause an increase in memory resource utilization. This vulnerability, published on 2025-02-05, is classified under CWE-401 (Memory Leak) and carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), indicating high severity due to its potential for availability impact.

Unauthenticated attackers with network access can exploit this issue with low attack complexity and no user interaction required. Exploitation involves sending the undisclosed requests, leading to memory exhaustion and potential denial-of-service conditions on the affected BIG-IP system.

Mitigation details are available in the F5 security advisory at https://my.f5.com/manage/s/article/K000140933. Note that software versions which have reached End of Technical Support (EoTS) are not evaluated.

EU & UK References

Vulnerability Data

When SNMP v1 or v2c are disabled on the BIG-IP, undisclosed requests can cause an increase in memory resource utilization. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

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.
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.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-29163Same product: F5 Big-Ip Access Policy Manager
CVE-2023-40534Same product: F5 Big-Ip Access Policy Manager
CVE-2026-42781Same product: F5 Big-Ip Access Policy Manager
CVE-2026-42920Same product: F5 Big-Ip Access Policy Manager
CVE-2026-34019Same product: F5 Big-Ip Access Policy Manager
CVE-2025-20058Same product: F5 Big-Ip Access Policy Manager
CVE-2025-21087Same product: F5 Big-Ip Access Policy Manager
CVE-2026-39455Same product: F5 Big-Ip Access Policy Manager
CVE-2026-40423Same product: F5 Big-Ip Access Policy Manager
CVE-2025-41433Same product: F5 Big-Ip Access Policy Manager

Affected Assets

f5
big-ip access policy manager
15.1.0 — 15.1.10 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.2
f5
big-ip advanced firewall manager
15.1.0 — 15.1.10 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.2
f5
big-ip advanced web application firewall
15.1.0 — 15.1.10 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.2
f5
big-ip analytics
15.1.0 — 15.1.10 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.2
f5
big-ip application acceleration manager
15.1.0 — 15.1.10 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.2
f5
big-ip application security manager
15.1.0 — 15.1.10 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.2
f5
big-ip application visibility and reporting
15.1.0 — 15.1.10 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.2
f5
big-ip automation toolchain
15.1.0 — 15.1.10 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.2
f5
big-ip carrier-grade nat
15.1.0 — 15.1.10 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.2
f5
big-ip container ingress services
15.1.0 — 15.1.10 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.2
+11 more product configuration(s) — see NVD for full list

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (static analysis, fuzzing, or runtime leak detection) directly finds missing deallocation.

Requiring documented development standards and tools can mandate memory-management disciplines that avoid leaks at introduction.

Engineering principles applied during development can require explicit resource-release patterns that stop memory leaks from being coded.

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.PS-06 mostly match
prevents

Secure SDLC practices directly enforce proper memory allocation/deallocation via coding standards, reviews, and tooling.

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.

finds

Security testing in development can detect unreleased memory, providing partial coverage of the weakness.

prevents

Secure development life cycle mandates memory-management practices that reduce missing-release defects.

prevents

Application security requirements can specify explicit memory-release rules, partially mitigating the weakness.

prevents

Secure system architecture and engineering principles include resource-management guidelines that address memory leaks.

prevents

Secure coding standards directly require proper allocation/deallocation, covering most of this weakness.

finds

Capacity management may detect memory exhaustion symptoms but does not prevent the coding flaw.

References