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Security Advisory

USN-4255-2: Linux kernel (HWE) vulnerabilities

USN-4255-2: Linux kernel (HWE) vulnerabilities




Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 16.04


USN-4255-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 18.04 LTS for Ubuntu 16.04 LTS.

It was discovered that the Linux kernel did not properly clear data structures on context switches for certain Intel graphics processors. A local attacker could use this to expose sensitive information. (CVE-2019-14615)

It was discovered that a race condition can lead to a use-after-free while destroying GEM contexts in the i915 driver for the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-7053)

CVEs contained in this USN include: CVE-2019-14615, CVE-2020-7053.

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

  • Xenial Stemcells
    • 97.x versions prior to 97.230
    • 621.x versions prior to 621.55
    • 170.x versions prior to 170.201
    • 315.x versions prior to 315.167
    • 456.x versions prior to 456.96
    • 250.x versions prior to 250.181
    • All other stemcells not listed.


Users of affected products are strongly encouraged to follow the mitigations below. The Cloud Foundry project recommends upgrading the following releases:

  • Xenial Stemcells
    • Upgrade 97.x versions to 97.230 or greater
    • Upgrade 621.x versions to 621.55 or greater
    • Upgrade 170.x versions to 170.201 or greater
    • Upgrade 315.x versions to 315.167 or greater
    • Upgrade 456.x versions to 456.96 or greater
    • Upgrade 250.x versions to 250.181 or greater
    • All other stemcells should be upgraded to the latest version available on


2020-01-28: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR