CVE-2023-23552
Published: 01 February 2023
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, ranked in the top 1.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
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
- 🇪🇺 ENISA EUVD: EUVD-2023-27652
Vulnerability details
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…
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increase in memory resource utilization. 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
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.
Limiting concurrent sessions directly prevents uncontrolled resource consumption by capping the number of active sessions per user or account.
Analysis identifies uncontrolled resource consumption indicative of denial-of-service or abuse attempts.
Contingency plan testing includes resource exhaustion scenarios to verify recovery, making it harder for attackers to sustain exploits that cause uncontrolled consumption.
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.
Alternate site allows resumption of operations if resource exhaustion at the primary site is exploited to cause unavailability.
Alternate telecommunications services enable resumption of essential functions when primary services become unavailable due to uncontrolled resource consumption.
The team can analyze and respond to resource exhaustion incidents, reducing the impact of attacks that exploit uncontrolled consumption weaknesses.
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.