CVE-2018-5509

CVE-2018-5509 is a high-severity vulnerability in F5 Big-ip Access Policy Manager with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Description

On F5 BIG-IP versions 13.0.0 or 12.1.0 - 12.1.3.1, when a specifically configured virtual server receives traffic of an undisclosed nature, TMM will crash and take the configured failover action, potentially causing a denial of service. The configuration which exposes this issue is not common and in general does not work when enabled in previous versions of BIG-IP. Starting in 12.1.0, BIG-IP will crash if the configuration which exposes this issue is enabled and the virtual server receives non TCP traffic. With the fix of this issue, additional configuration validation logic has been added to prevent this configuration from being applied to a virtual server. There is only data plane exposure to this issue with a non-standard configuration. There is no control plane exposure.

Frequently asked questions

What is CVE-2018-5509?
On F5 BIG-IP versions 13.0.0 or 12.1.0 - 12.1.3.1, when a specifically configured virtual server receives traffic of an undisclosed nature, TMM will crash and take the configured failover action, potentially causing a denial of service. The configuration which exposes this issue is not common and in general does not work when enabled in previous versions of BIG-IP. Starting in 12.1.0, BIG-IP will crash if the configuration which exposes this issue is enabled and the virtual server receives non TCP traffic. With the fix of this issue, additional configuration validation logic has been added to prevent this configuration from being applied to a virtual server. There is only data plane exposure to this issue with a non-standard configuration. There is no control plane exposure.
How severe is CVE-2018-5509?
CVE-2018-5509 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2018-5509 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-5509?
CVE-2018-5509 primarily affects F5 Big-ip Access Policy Manager. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-5509?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-5509 published?
CVE-2018-5509 was published on 2018-03-22 and last updated on 2026-06-17.

References

Affected products (8)

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