Severity

Medium

Vendor

Canonical Ubuntu

Versions Affected

• Canonical Ubuntu 16.04
• Canonical Ubuntu 18.04

Description

Eyal Ronen, Kenneth G. Paterson, and Adi Shamir discovered that GnuTLS was vulnerable to a timing side-channel attack known as the “Lucky Thirteen” issue. A remote attacker could possibly use this issue to perform plaintext-recovery attacks via analysis of timing data. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2018-10844, CVE-2018-10845, CVE-2018-10846)

Tavis Ormandy discovered that GnuTLS incorrectly handled memory when verifying certain X.509 certificates. A remote attacker could use this issue to cause GnuTLS to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.04 LTS, Ubuntu 18.10, and Ubuntu 19.04. (CVE-2019-3829)

It was discovered that GnuTLS incorrectly handled certain post-handshake messages. A remote attacker could use this issue to cause GnuTLS to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.10 and Ubuntu 19.04. (CVE-2019-3836)

CVEs contained in this USN include: CVE-2018-10844, CVE-2018-10845, CVE-2018-10846, CVE-2019-3829, CVE-2019-3836

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

• Cloud Foundry BOSH xenial-stemcells are vulnerable, including:
  • 315.x versions prior to 315.36
  • 250.x versions prior to 250.58
  • 170.x versions prior to 170.78
  • 97.x versions prior to 97.108
  • All other stemcells not listed.
• All versions of Cloud Foundry cflinuxfs3 prior to 0.93.0

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 315.x versions to 315.36
  • Upgrade 250.x versions to 250.58
  • Upgrade 170.x versions to 170.78
  • Upgrade 97.x versions to 97.108
  • All other stemcells should be upgraded to the latest version available on bosh.io.
• The Cloud Foundry project recommends that Cloud Foundry deployments run with cflinuxfs3 version 0.93.0 or later.

References

• USN-3999-1
• CVE-2018-10844
• CVE-2018-10845
• CVE-2018-10846
• CVE-2019-3829
• CVE-2019-3836