Severity

Medium

Vendor

Canonical Ubuntu

Versions Affected

• Canonical Ubuntu 16.04

Description

USN-3901-1 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.

Jann Horn discovered that the userfaultd implementation in the Linux kernel did not properly restrict access to certain ioctls. A local attacker could use this possibly to modify files. (CVE-2018-18397)

It was discovered that the crypto subsystem of the Linux kernel leaked uninitialized memory to user space in some situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-19854)

Jann Horn discovered a race condition in the fork() system call in the Linux kernel. A local attacker could use this to gain access to services that cache authorizations. (CVE-2019-6133)

CVEs contained in this USN include: CVE-2018-19854, CVE-2018-18397, CVE-2019-6133

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

• Cloud Foundry BOSH xenial-stemcells are vulnerable, including:
  • 250.x versions prior to 250.21
  • 170.x versions prior to 170.39
  • 97.x versions prior to 97.66
  • 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 xenial-stemcells:
  • Upgrade 250.x versions to 250.21
  • Upgrade 170.x versions to 170.39
  • Upgrade 97.x versions to 97.66
  • All other stemcells should be upgraded to the latest version available on bosh.io.

References

• USN-3901-2
• CVE-2018-19854
• CVE-2018-18397
• CVE-2019-6133