--- title: "CVE-2016-9756\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-2016-9756?format=md keywords: index, follow --- # CVE-2016-9756 Publication date 28 December 2016 Last updated 4 July 2026 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **5.5 · Medium** [Score breakdown](https://ubuntu.com/security/CVE-2016-9756?format=md#impact-score) Toggle side navigation ## Description arch/x86/kvm/emulate.c in the Linux kernel before 4.8.12 does not properly initialize Code Segment (CS) in certain error cases, which allows local users to obtain sensitive information from kernel stack memory via a crafted application. ### From the Ubuntu Security Team Dmitry Vyukov discovered that the KVM implementation in the Linux kernel did not properly initialize the Code Segment (CS) in certain error cases. A local attacker could use this to expose sensitive information (kernel memory). [Read the notes from the security team](https://ubuntu.com/security/CVE-2016-9756?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | linux | 17.04 zesty | Not affected | | 16.10 yakkety | Fixed 4.8.0-34.36 | | 16.04 LTS xenial | Fixed 4.4.0-59.80 | | 14.04 LTS trusty | Fixed 3.13.0-107.154 | | 12.04 LTS precise | Fixed 3.2.0-120.163 | | linux-armadaxp | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Fixed 3.2.0-1681.108 | | linux-aws | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Fixed 4.4.0-1003.12 | | 14.04 LTS trusty | Not affected | | 12.04 LTS precise | Not in release | | linux-flo | 17.04 zesty | Not in release | | 16.10 yakkety | Not affected | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-gke | 17.04 zesty | Not in release | | 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 | 17.04 zesty | Not affected | | 16.10 yakkety | Not affected | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-grouper | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-hwe | 17.04 zesty | Not in release | | 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 | 17.04 zesty | Not in release | | 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 | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-linaro-shared | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-linaro-vexpress | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-lts-quantal | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-lts-raring | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-lts-saucy | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-lts-trusty | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Fixed 3.13.0-107.154~precise1 | | linux-lts-utopic | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-lts-vivid | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Fixed 3.19.0-79.87~14.04.1 | | 12.04 LTS precise | Not in release | | linux-lts-wily | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-lts-xenial | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Fixed 4.4.0-59.80~14.04.1 | | 12.04 LTS precise | Not in release | | linux-maguro | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-mako | 17.04 zesty | Not in release | | 16.10 yakkety | Not affected | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-manta | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-qcm-msm | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Ignored end of life | | linux-raspi2 | 17.04 zesty | Not affected | | 16.10 yakkety | Not affected | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-snapdragon | 17.04 zesty | Not affected | | 16.10 yakkety | Not affected | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Not in release | | linux-ti-omap4 | 17.04 zesty | Not in release | | 16.10 yakkety | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | 12.04 LTS precise | Fixed 3.2.0-1498.125 | --- * [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-2016-9756?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 ### 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 [d1442d8](https://git.kernel.org/linus/d1442d85cc30ea75f7d399474ca738e0bc96f715), fixed by [2117d53](https://git.kernel.org/linus/2117d5398c81554fbf803f5fd1dc55eb78216c0c) | ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 5.5 · Medium * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Local | | Attack complexity | Low | | Privileges required | Low | | User interaction | None | | Scope | Unchanged | | Confidentiality impact | High | | Integrity impact | None | | Availability impact | None | * Scores | Parameter | Value | | --- | --- | | Base score | 5.5 · Medium | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-9756) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-9756) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-9756) * [Debian](https://security-tracker.debian.org/tracker/CVE-2016-9756) ### Related Ubuntu Security Notices (USN) + [USN-3168-2](https://usn.ubuntu.com/USN-3168-2) + Linux kernel (Trusty HWE) vulnerabilities + 11 January 2017 + [USN-3168-1](https://usn.ubuntu.com/USN-3168-1) + Linux kernel vulnerabilities + 11 January 2017 + [USN-3169-2](https://usn.ubuntu.com/USN-3169-2) + Linux kernel (Xenial HWE) vulnerabilities + 11 January 2017 + [USN-3169-1](https://usn.ubuntu.com/USN-3169-1) + Linux kernel vulnerabilities + 11 January 2017 + [USN-3170-1](https://usn.ubuntu.com/USN-3170-1) + Linux kernel vulnerabilities + 11 January 2017 + [USN-3167-1](https://usn.ubuntu.com/USN-3167-1) + Linux kernel vulnerabilities + 11 January 2017 + [USN-3167-2](https://usn.ubuntu.com/USN-3167-2) + Linux kernel (OMAP4) vulnerabilities + 11 January 2017 ### Other references * *