CVE-2019-5609

CVE-2019-5609 is a high-severity vulnerability in Freebsd 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-787.

Key facts

Description

In FreeBSD 12.0-STABLE before r350619, 12.0-RELEASE before 12.0-RELEASE-p9, 11.3-STABLE before r350619, 11.3-RELEASE before 11.3-RELEASE-p2, and 11.2-RELEASE before 11.2-RELEASE-p13, the bhyve e1000 device emulation used a guest-provided value to determine the size of the on-stack buffer without validation when TCP segmentation offload is requested for a transmitted packet. A misbehaving bhyve guest could overwrite memory in the bhyve process on the host.

Frequently asked questions

What is CVE-2019-5609?
In FreeBSD 12.0-STABLE before r350619, 12.0-RELEASE before 12.0-RELEASE-p9, 11.3-STABLE before r350619, 11.3-RELEASE before 11.3-RELEASE-p2, and 11.2-RELEASE before 11.2-RELEASE-p13, the bhyve e1000 device emulation used a guest-provided value to determine the size of the on-stack buffer without validation when TCP segmentation offload is requested for a transmitted packet. A misbehaving bhyve guest could overwrite memory in the bhyve process on the host.
How severe is CVE-2019-5609?
CVE-2019-5609 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 high, and availability none.
Is CVE-2019-5609 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-5609?
CVE-2019-5609 primarily affects Freebsd. In total, 24 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-5609?
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-2019-5609 published?
CVE-2019-5609 was published on 2019-08-30 and last updated on 2026-06-17.

References

Affected products (24)

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