The latest security information on Intel® products.

DCI Policy Update

Intel ID:
Product family:
5th and 6th generation Intel® Xeon® Processor E3 family, Intel® Xeon® Scalable processors, and Intel® Xeon® Processor D family
Impact of vulnerability:
Information Disclosure, Escalation of Privilege
Severity rating:
Original release:
Last revised:


Intel is releasing Direct Connect Interface (DCI) policy update.


Existing UEFI setting restrictions for DCI (Direct Connect Interface) in 5th and 6th generation Intel® Xeon® Processor E3 Family, Intel® Xeon® Scalable processors, and Intel® Xeon® Processor D Family can potentially allow a limited physical presence attacker to access platform secrets via debug interfaces.

Affected products:

•    Note:  Client platforms are not included in the following table, because all client platforms are expected to have EFI Secure Boot enabled & the UEFI Variable controlling DCI set to default disabled.

Potentially Affected Platform

Mitigated Platform sample code

Code Name Purley:

Intel® Xeon® Scalable processors

Available in Post Launch Release 7

or later on VIP @

Code Name Greenlow:

Intel® Xeon® Processor E3 v6 Family (Kaby Lake)

Intel® Xeon® Processor E3 v5 Family (Skylake)

Perform a code review based on TA content and remove the vulnerability as necessary. 

Code Name Bakerville:

Intel® Xeon® Processor D Family (Skylake-D)

Available in Post Launch Release 2

or later on VIP @

Code Name Harrisonville:

Intel® Atom ™ Processor C Series (Denverton)

Perform a code review based on TA content and remove the vulnerability as necessary. 



Intel highly recommends that all potentially affected platforms modify the DCI policy such that DCI control is disabled.  Below are references to Purley, Bakerville, and Greenlow codebases.

•    Sample Code Filename:

        Greenlow filename:  PeiPchPolicyDebugLib.c

        Purley/Bakerville filename:  PeiPchPolicyUpdate.c

•    Code to change in Sample Code File:

        PchPolicy->DciConfig.DciEn  = 0;

        PchPolicy->DciConfig.DciAutoDetect = 0;


Intel would like to thank Jesse Michael from Eclypsium for reporting this issue and working with us on coordinated disclosure.

Revision History

Revision Date Description
1.0 07/09/2018 Initial Release

CVE Name: CVE-2018-3652

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