Cyber Resilience

CVE-2023-23552

DoS in F5 Big-Ip Advanced Web Application Firewall 13.1.0 – 13.1.5

Published
01 February 2023
Modified
21 November 2024
Patch / 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 0.015 73th percentile
Risk Priority 81 floored blend · peak EPSS

Summary

CVE-2023-23552 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in F5 Big-Ip Advanced Web Application Firewall. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Exhaustion Flood (T1499.001); ranked in the top 27% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

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-2023-23552 is an uncontrolled resource consumption vulnerability (CWE-400) affecting F5 BIG-IP Advanced WAF and BIG-IP ASM when a security policy is attached to a virtual server. The flaw impacts versions 17.0.x prior to 17.0.0.2, 16.1.x prior to 16.1.3.3, 15.1.0 prior to 15.1.8, 14.1.x prior to 14.1.5.3, and all releases in the 13.1.x branch; older releases that have reached end of technical support are outside the scope of the evaluation. Successful exploitation produces an increase in memory utilization that can impair availability.

Unauthenticated remote attackers can trigger the issue by sending specially crafted requests to an affected virtual server. Because the CVSS vector shows network attack vector, low complexity, and no required privileges or user interaction, the requests can originate from anywhere on the network and result in denial-of-service conditions without authentication.

F5 has published mitigation guidance in knowledge article K17542533, which addresses the affected software branches and directs customers to the corresponding fixes or configuration changes. The article also notes that unsupported versions are not evaluated for this vulnerability.

The EPSS score has reached a peak and current value of 0.6334, indicating sustained exploitation interest after disclosure.

EU & UK References

Vulnerability Data

On versions 17.0.x before 17.0.0.2, 16.1.x before 16.1.3.3, 15.1.0 before 15.1.8, 14.1.x before 14.1.5.3, and all versions of 13.1.x, when a BIG-IP Advanced WAF or BIG-IP ASM security policy is configured on a virtual server, undisclosed requests can cause an…

more

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

T1499.001 OS Exhaustion Flood Impact
Adversaries may launch a denial of service (DoS) attack targeting an endpoint's operating system (OS).
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.
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.
T1499.002 Service Exhaustion Flood Impact
Adversaries may target the different network services provided by systems to conduct a denial of service (DoS).
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-2025-58474Same product: F5 Big-Ip Advanced Web Application Firewall
CVE-2024-21789Same product: F5 Big-Ip Advanced Web Application Firewall
CVE-2025-54858Same product: F5 Big-Ip Advanced Web Application Firewall
CVE-2023-24594Same product: F5 Big-Ip Advanced Web Application Firewall
CVE-2025-20058Same product: F5 Big-Ip Advanced Web Application Firewall
CVE-2025-21087Same product: F5 Big-Ip Advanced Web Application Firewall
CVE-2024-23308Same product: F5 Big-Ip Advanced Web Application Firewall
CVE-2023-22664Same product: F5 Big-Ip Application Security Manager
CVE-2025-61938Same product: F5 Big-Ip Advanced Web Application Firewall
CVE-2026-41227Same product: F5 Big-Ip Advanced Web Application Firewall

Affected Assets

f5
big-ip advanced web application firewall
13.1.0 — 13.1.5 · 14.1.0 — 14.1.5.3 · 15.1.0 — 15.1.8
f5
big-ip application security manager
13.1.0 — 13.1.5 · 14.1.0 — 14.1.5.3 · 15.1.0 — 15.1.8

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.

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
prevents

Explicitly requires monitoring and maintaining resource capacity, directly addressing uncontrolled consumption to preserve availability.

DE.CM-09 partial match
prevents

Continuous monitoring of computing resources can detect resource exhaustion but does not itself enforce allocation limits.

PR.IR-03 partial match
prevents

Resilience mechanisms such as avoiding single points of failure indirectly reduce impact of resource exhaustion.

PR.PS-01 partial match
prevents

Hardened configuration baselines can include resource quotas and limits that constrain consumption.

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

Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.

prevents

By continuously monitoring utilization, stress-testing peak loads, and maintaining documented plans to scale or throttle resources, the control directly limits an attacker’s ability to drive a system into uncontrolled resource exhaustion.

finds

Pre-agreed severity-based prioritization and resource allocation during incident triage reduce the likelihood that an attacker-induced resource exhaustion will overwhelm the organization before corrective action is taken.

mitigates

Business-continuity plans that include resource-management controls reduce the likelihood that an attacker can trigger uncontrolled resource consumption by forcing the system into a degraded or fallback state.

mitigates

Defining RTOs and capacity requirements for ICT services during business-impact analysis forces organizations to provision sufficient resources and throttling mechanisms, reducing the likelihood that an attacker can induce denial-of-service through uncontrolled resource consumption.

finds

Early notification of anomalous resource consumption or system malfunctions enables throttling or isolation before availability is lost.

References