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Security advisories | Feb 26, 2019

Spectre and Meltdown Follow-up

Intel patches for the Meltdown and Spectre vulnerabilities have been attributed with causing loss of data or corruption of data in certain cases. Intel is advising customers to refrain from updating their firmware until full patch testing is complete. Windows has released an out of band patch (KB4078130) that keeps protection for vulnerability variants 1 (CVE-2017-5753) and 3 (CVE-2017-5754),while removing the problematic fix for variant 2 (CVE-2017-5715) [1].

AMD processors are not affected by Meltdown. Early patches for AMD devices against Spectre caused an error that left some AMD devices unbootable. The issue has been fixed and patches are available.

Issues with Microsoft’s security updates and Antivirus compatibility were reported early on. Microsoft will not deliver Spectre and Meltdown patches unless the AV vendor has added a specific registry key. Windows Defender Antivirus, System Center Endpoint Protection, and Microsoft Security Essentials are all patch compatible.

Performance issues relating to security patches vary depending on the OS version and the age of the machine. At this time it does not appear that either the Meltdown or Spectre vulnerabilities have been exploited in the wild. Opportunistic threat actors have attempted to capitalize on the confusion surrounding these vulnerabilities by inserting malware into fake non-vendor patches [2].

What we’re doing about it

  • The eSentire Threat Intelligence team is monitoring this ongoing event for further information

What you should do about it

  • For affected Intel processors running the recently released microcode, apply update KB4078130 [2]. If you have not deployed microcode updates, but wish to apply mitigations immediately, we recommend contacting your vendor(s) for clarification on patch guidance.
  • If running an affected AMD processor, apply the most recent Microsoft patch
  • Check with AV vendor to ensure compatibility with patches
  • Only install security patches from trusted vendors

Additional Information

  • For a full list of affected Intel devices, see Intel’s microcode revision guidance document [4].
  • For affected devices with ARM processors and associated mitigation tactics, please see the official ARM Developer website [5].
  • AMD patches are not available for versions 1511, 1607, and 1703 of Windows 10 and for Windows Server 2016 and Windows 10 Enterprise.