Severity

High

Vendor

Canonical Ubuntu

Versions Affected

• Canonical Ubuntu 14.04

Description

Nick Peterson discovered that the Linux kernel did not properly handle debug exceptions following a MOV/POP to SS instruction. A local attacker could use this to cause a denial of service (system crash). This issue only affected the amd64 architecture. (CVE-2018-8897)

Andy Lutomirski discovered that the KVM subsystem of the Linux kernel did not properly emulate the ICEBP instruction following a MOV/POP to SS instruction. A local attacker in a KVM virtual machine could use this to cause a denial of service (guest VM crash) or possibly escalate privileges inside of the virtual machine. This issue only affected the i386 and amd64 architectures. (CVE-2018-1087)

Andy Lutomirski discovered that the Linux kernel did not properly perform error handling on virtualized debug registers. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-1000199)

Affected Cloud Foundry Products and Versions

Severity is high unless otherwise noted.

• Cloud Foundry BOSH stemcells are vulnerable, including:
  • 3363.x versions prior to 3363.61
  • 3421.x versions prior to 3421.59
  • 3445.x versions prior to 3445.45
  • 3468.x versions prior to 3468.42
  • 3541.x versions prior to 3541.25
  • 3586.x versions prior to 3586.7
  • All other stemcells not listed.

Mitigation

OSS users are strongly encouraged to follow one of the mitigations below:

• The Cloud Foundry project recommends upgrading the following BOSH stemcells:
  • Upgrade 3363.x versions to 3363.61
  • Upgrade 3421.x versions to 3421.59
  • Upgrade 3445.x versions to 3445.45
  • Upgrade 3468.x versions to 3468.42
  • Upgrade 3541.x versions to 3541.25
  • Upgrade 3586.x versions to 3586.7
  • All other stemcells should be upgraded to the latest version available on bosh.io.

References

• USN-3641-1
• CVE-2018-1000199
• CVE-2018-1087
• CVE-2018-8897