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Security Advisory

USN-4041-2: Linux kernel (HWE) update

USN-4041-2: Linux kernel (HWE) update




Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 14.04


USN-4041-1 provided updates for the Linux kernel in Ubuntu. This update provides the corresponding updates for the Linux kernel for Ubuntu 16.04 ESM.

USN-4017-2 fixed vulnerabilities in the Linux kernel. Unfortunately, the update introduced a regression that interfered with networking applications that setup very low SO_SNDBUF values. This update fixes the problem.

We apologize for the inconvenience.

Jonathan Looney discovered that the Linux kernel could be coerced into segmenting responses into multiple TCP segments. A remote attacker could construct an ongoing sequence of requests to cause a denial of service. (CVE-2019-11479)

CVEs contained in this USN include: CVE-2019-11479

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

  • Cloud Foundry BOSH trusty-stemcells are vulnerable, including:
    • 3586.x versions prior to 3586.141
    • 3541.x versions prior to 3541.135
    • 3468.x versions prior to 3468.143
    • All other stemcells not listed.


Users of affected products are strongly encouraged to follow one of the mitigations below:

  • The Cloud Foundry project recommends upgrading the following BOSH trusty-stemcells:
    • Upgrade 3586.x versions to 3586.141
    • Upgrade 3541.x versions to 3541.135
    • Upgrade 3468.x versions to 3468.143
    • All other stemcells should be upgraded to the latest version available on


Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR