CVE-2015-2877

Publication date 3 March 2017

Last updated 4 August 2025

Ubuntu priority

Low

Why this priority?

Cvss 3 Severity Score

3.3 · Low

Score breakdown

Description

Kernel Samepage Merging (KSM) in the Linux kernel 2.6.32 through 4.x does not prevent use of a write-timing side channel, which allows guest OS users to defeat the ASLR protection mechanism on other guest OS instances via a Cross-VM ASL INtrospection (CAIN) attack. NOTE: the vendor states "Basically if you care about this attack vector, disable deduplication." Share-until-written approaches for memory conservation among mutually untrusting tenants are inherently detectable for information disclosure, and can be classified as potentially misunderstood behaviors rather than vulnerabilities

Read the notes from the security team

Mitigation

If qemu-kvm is installed, set KSM_ENABLED=0 in /etc/default/qemu-kvm, otherwise will need to echo -n 0 > /sys/kernel/mm/ksm/run

Status

Package Ubuntu Release Status
linux-flo 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Ignored end of life
16.04 LTS xenial Not in release
15.10 wily Ignored end of life
15.04 vivid Ignored end of life
14.10 utopic Ignored end of life, was needs-triage
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux 18.10 cosmic Ignored end of life
18.04 LTS bionic
Not affected
17.10 artful Ignored end of life
17.04 zesty Ignored end of life
16.10 yakkety Ignored end of life
16.04 LTS xenial
Not affected
15.10 wily Ignored end of life
15.04 vivid Ignored end of life, was deferred
14.10 utopic Ignored end of life, was deferred
14.04 LTS trusty
Not affected
12.04 LTS precise Ignored end of life
linux-armadaxp 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-aws 18.10 cosmic Ignored end of life
18.04 LTS bionic
Not affected
17.10 artful Not in release
17.04 zesty Not in release
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-azure 18.10 cosmic Ignored end of life
18.04 LTS bionic
Not affected
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
linux-azure-edge 18.10 cosmic Not in release
18.04 LTS bionic
Not affected
16.04 LTS xenial Ignored end of standard support
14.04 LTS trusty Not in release
linux-ec2 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-euclid 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-fsl-imx51 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-gcp 18.10 cosmic Ignored end of life
18.04 LTS bionic
Not affected
17.10 artful Not in release
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
linux-gke 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
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-goldfish 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Ignored end of life
16.10 yakkety Ignored end of life
16.04 LTS xenial Not in release
15.10 wily Ignored end of life
15.04 vivid Ignored end of life
14.10 utopic Ignored end of life
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-grouper 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Ignored end of life
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-hwe 18.10 cosmic Not in release
18.04 LTS bionic
Not affected
17.10 artful Not in release
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 18.10 cosmic Not in release
18.04 LTS bionic
Not affected
17.10 artful Not in release
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-kvm 18.10 cosmic Ignored end of life
18.04 LTS bionic
Not affected
17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-linaro-omap 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-linaro-shared 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-linaro-vexpress 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-lts-quantal 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-lts-raring 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life, was needs-triage
linux-lts-saucy 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-lts-trusty 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-lts-utopic 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-lts-vivid 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-lts-wily 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-lts-xenial 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.04 LTS trusty
Not affected
12.04 LTS precise Not in release
linux-maguro 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-mako 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Ignored end of life
16.04 LTS xenial Not in release
15.10 wily Ignored end of life
15.04 vivid Ignored end of life
14.10 utopic Ignored end of life, was needs-triage
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-manta 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Ignored end of life
15.04 vivid Ignored end of life
14.10 utopic Ignored end of life, was needs-triage
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-mvl-dove 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-oem 18.10 cosmic Ignored end of life
18.04 LTS bionic
Not affected
17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-qcm-msm 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life
linux-raspi2 18.10 cosmic Ignored end of life
18.04 LTS bionic Ignored end of standard support
17.10 artful Ignored end of life
17.04 zesty Ignored end of life
16.10 yakkety Ignored end of life
16.04 LTS xenial Not in release
15.10 wily Ignored end of life
15.04 vivid Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Not in release
linux-snapdragon 18.10 cosmic Not in release
18.04 LTS bionic Ignored end of standard support
17.10 artful Ignored end of life
17.04 zesty Ignored end of life
16.10 yakkety Ignored end of life
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-ti-omap4 18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.10 yakkety Not in release
16.04 LTS xenial Not in release
15.10 wily Not in release
15.04 vivid Not in release
14.10 utopic Not in release
14.04 LTS trusty Not in release
12.04 LTS precise Ignored end of life

Notes

tyhicks

The behavior represented by CVE-2015-2877 is inherent to Kernel Samepage Merging. To mitigate the issue, follow the steps above to disable KSM.

Severity score breakdown

Parameter Value
Base score 3.3 · Low
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality Low
Integrity impact None
Availability impact None
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

References

Other references