F5 BIG-IP TMM Crash via Client HTTP/2 + MRF Router iRule Fusion
CVE-2023-40534 Published on October 10, 2023
BIG-IP HTTP/2 vulnerability
When a client-side HTTP/2 profile and the HTTP MRF Router option are enabled for a virtual server, and an iRule using the HTTP_REQUEST event or Local Traffic Policy are associated with the virtual server, undisclosed requests can cause TMM to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Vulnerability Analysis
CVE-2023-40534 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is a Memory Leak Vulnerability?
The software does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. This is often triggered by improper handling of malformed data or unexpectedly interrupted sessions. In some languages, developers are responsible for tracking memory allocation and releasing the memory. If there are no more pointers or references to the memory, then it can no longer be tracked and identified for release.
CVE-2023-40534 has been classified to as a Memory Leak vulnerability or weakness.
Products Associated with CVE-2023-40534
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Affected Versions
F5 BIG-IP:- Version 17.1.0 and below 17.1.0.3.0.23.4-ENG is affected.
- Version 16.1.0 and below 16.1.4.1.0.13.5-ENG is affected.
- Version 15.1.0 and below * is unaffected.
- Version 14.1.0 and below * is unaffected.
- Version 13.1.0 and below * is unaffected.
- Version 1.6.0 and below * is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.