--- title: "CVE-2016-4440\n | Ubuntu" description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/CVE-2016-4440?format=md keywords: index, follow --- # CVE-2016-4440 Publication date 27 June 2016 Last updated 4 July 2026 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **7.8 · High** [Score breakdown](https://ubuntu.com/security/CVE-2016-4440?format=md#impact-score) Toggle side navigation ## Description arch/x86/kvm/vmx.c in the Linux kernel through 4.6.3 mishandles the APICv on/off state, which allows guest OS users to obtain direct APIC MSR access on the host OS, and consequently cause a denial of service (host OS crash) or possibly execute arbitrary code on the host OS, via x2APIC mode. ### From the Ubuntu Security Team XXX-no-USN-needed-see-NOTE-XXX It was discovered that the Linux kernel mishandles the APICv on/off state, allowing guest OS users direct APIC MSR access on the host OS. A local attacker could use this to cause a denial of service (host OS crash), or possibly execute arbitrary code with administrative privileges in the host OS. [Read the notes from the security team](https://ubuntu.com/security/CVE-2016-4440?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | linux | 16.10 yakkety | Not affected | | 16.04 LTS xenial | Not affected | | 15.10 wily | Not affected | | 14.04 LTS trusty | Not affected | | 12.04 LTS precise | Not affected | | linux-armadaxp | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not affected | | linux-aws | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not affected | | 12.04 LTS precise | Not in release | | linux-flo | 16.10 yakkety | Not affected | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not affected | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-gke | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-goldfish | 16.10 yakkety | Not affected | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not affected | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-grouper | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-hwe | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-hwe-edge | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-linaro-omap | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-linaro-shared | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-linaro-vexpress | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-lts-quantal | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-lts-raring | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-lts-saucy | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-lts-trusty | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not affected | | linux-lts-utopic | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-lts-vivid | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-lts-wily | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-lts-xenial | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not affected | | 12.04 LTS precise | Not in release | | linux-maguro | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-mako | 16.10 yakkety | Not affected | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not affected | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-manta | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not affected | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-qcm-msm | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-raspi2 | 16.10 yakkety | Not affected | | 16.04 LTS xenial | Not affected | | 15.10 wily | Not affected | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-snapdragon | 16.10 yakkety | Not affected | | 16.04 LTS xenial | Not affected | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-ti-omap4 | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 15.10 wily | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not affected | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) * [Patch details](https://ubuntu.com/security/CVE-2016-4440?format=md#patch-details) ## Notes --- ### [jdstrand](https://launchpad.net/~jdstrand) android kernels (flo, goldfish, grouper, maguro, mako and manta) are not supported on the Ubuntu Touch 14.10 and earlier preview kernels linux-lts-saucy no longer receives official support linux-lts-quantal no longer receives official support --- ### [sbeattie](https://launchpad.net/~sbeattie) according to kvm-devel thread, introduced in 5c919412fe61c35947816fdbd5f7bd09fe0dd073 note for xenial kernels, both the commit that introduced the issue and the fix were pulled in to the 4.4.0-32.51 kernel, so at no time were users exposed to this vulnerability. ### Patch details For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) | Package | Patch details | | --- | --- | | linux | * Introduced by [5c91941](https://git.kernel.org/linus/5c919412fe61c35947816fdbd5f7bd09fe0dd073), fixed by [3ce424e](https://git.kernel.org/linus/3ce424e45411cf5a13105e0386b6ecf6eeb4f66f) | ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 7.8 · High * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Local | | Attack complexity | Low | | Privileges required | Low | | User interaction | None | | Scope | Unchanged | | Confidentiality impact | High | | Integrity impact | High | | Availability impact | High | * Scores | Parameter | Value | | --- | --- | | Base score | 7.8 · High | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-4440) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-4440) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-4440) * [Debian](https://security-tracker.debian.org/tracker/CVE-2016-4440) ### Other references * * * *