Severity

Medium

Vendor

Canonical Ubuntu

Versions Affected

• Canonical Ubuntu 14.04

Description

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.

Mitigation

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 bosh.io.

References

• USN-4041-2
• CVE-2019-11479