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Me, myself & IT

Meltdown, Spectre, Spectre-NG and Foreshadow Update Check Utility

Background Information
Implementation and Build Details
Authenticity and Integrity
Makefile and Build Instructions


The Windows application BTI_RDCL.EXE displays the status of the mitigations for the vulnerabilities CVE-2017-5715 alias Branch Target Injection and CVE-2017-5754 alias Rogue Data Cache Load, better known by their nicknames Meltdown and Spectre, as well as the mitigations for the vulnerability CVE-2018-3639 alias Speculative Store Bypass, also known as Spectre-NG or Variant 4, CVE-2018-3640 alias Rogue System Register Read, also known as Spectre-NG or Variant 3a, and CVE-2018-3615, CVE-2018-3620 plus CVE-2018-3646 alias L1 Terminal Fault, also known by its nickname Foreshadow.
The mitigations are installed by one of the security updates 4056888, 4056890, 4056891, 4056892, 4056893, 4056894, 4056895, 4056896, 4056897, 4056898 and 4056899, the subsequent updates 4057142, 4057144, 4075199, 4075200, 4057400, 4057401, 4057402, 4073290, 4073291, 4073576 and 4073578, and their successors.

Note: the status of the mitigations for the vulnerabilities CVE-2017-5753 alias Bounds Check Bypass and CVE-2018-3693 alias Bounds Check Bypass Store can’t be shown: every sequence of machine code which is susceptible to these vulnerabilities needs to be fixed individually!

Background Information

The MSKB articles 4072698, 4072699, 4073065, 4073119, 4073225, 4073229, 4073237, 4073707, 4073757, 4078130 and 4078407 provide information about the updates.

The MSKB articles 4090007, 4091663, 4091664, 4091666, 4093836, 4100347, 4346084, 4346085, 4346086, 4346087, 4346088 and 4465065 provide information about the microcode updates distributed through the Microsoft Update Catalog.

The posts Mitigating speculative execution side channel hardware vulnerabilities, KVA Shadow: Mitigating Meltdown on Windows, Analysis and mitigation of speculative store bypass (CVE-2018-3639) and Analysis and mitigation of L1 Terminal Fault (L1TF) on Microsoft’s Security Research and Defense Blog give additional information.

The article series Deep Dive: Introduction to Speculative Execution Side Channel Methods, Deep Dive: Analyzing Potential Bounds Check Bypass Vulnerabilities, Deep Dive: Intel Analysis of Speculative Behavior of SWAPGS and Segment Registers, Deep Dive: Indirect Branch Restricted Speculation, Deep Dive: Single Thread Indirect Branch Predictors, Deep Dive: Indirect Branch Predictor Barrier, Deep Dive: Retpoline: A Branch Target Injection Mitigation, Deep Dive: Managed Runtime Speculative Execution Side Channel Mitigations, Deep Dive: Intel Analysis of Microarchitectural Data Sampling, Deep Dive: Intel Analysis of L1 Terminal Fault, Deep Dive: Snoop-assisted L1 Data Sampling, Deep Dive: Intel® Transactional Synchronization Extensions (Intel® TSX) Asynchronous Abort, Deep Dive: Load Value Injection, Deep Dive: Special Register Buffer Data Sampling and Deep Dive: CPUID Enumeration and Architectural MSRs, plus More information on SWAPGS and Speculative only Segment Loads, An Optimized Mitigation Approach for Load Value Injection and Refined Speculative Execution Terminology give more details, while Processors Affected: Speculative Behavior of SWAPGS and Segment Registers, Processors Affected: Microarchitectural Data Sampling, Processors Affected: L1 Terminal Fault, Processors Affected: L1D Eviction Sampling, Processors Affected: Vector Register Sampling, Processors Affected: Snoop-assisted L1 Data Samplingm Processors Affected: Load Value Injection and Processors Affected: Special Register Buffer Data Sampling list the affected Intel processors.


[Screen shot of BTI_RDCL.EXE without security update for 'Meltdown' (CVE-2017-5754), 'Spectre' (CVE-2017-5715, CVE-2017-5753) and 'Spectre-NG' (CVE-2018-3639, CVE-2018-3640)] Without security update installed, BTI_RDCL.EXE displays two message boxes like that shown on the right.

With security update installed, BTI_RDCL.EXE displays two message boxes like those shown below.

[Screen shot of BTI_RDCL.EXE with active mitigation for 'Meltdown' (CVE-2017-5754)] [Screen shot of BTI_RDCL.EXE with active mitigation for 'Spectre' (CVE-2017-5715)]

Implementation and Build Details

BTI_RDCL.EXE is a pure Win32 application, written in ANSI C, built with the Platform SDK for Windows Server 2003 R2 Microsoft Visual C++ Compiler 2010 SP1 from update 2519277, but without the MSVCRT libraries, for use on Windows 2000 XP and newer versions of Windows NT as well as Windows PE.

Authenticity and Integrity

BTI_RDCL.EXE is digitally signed using an X.509 certificate issued by WEB.DE TrustCenter E-Mail Certification Authority.
Serial number of the certificate
0x0465CEF9 = 73780985
Fingerprint of the certificate
MD5: 33 33 6e 1d 26 18 a7 c2 be 87 11 68 05 2c 70 09
SHA-1: 8c 5b 75 21 40 41 77 ac 54 13 13 02 06 6b b0 69 10 2e 83 0e
Download and install the CA and root X.509 certificates of WEB.DE to validate and verify the digital signature.

Note: unfortunately WEB.DE abandoned their trust center in 2018 and removed all pages and download links in 2019; fortunately the Wayback Machine archived the TrustCenter page, the CA and the root certificate.

Note: due to its counter signature alias timestamp the digital signature remains valid past the X.509 certificates expiration date!

Makefile and Build Instructions

Optionally perform the following 4 simple steps to build BTI_RDCL.EXE from the source and sign it with your own X.509 certificate.
  1. Download the makefile BTI_RDCL.MAK and save it in an arbitrary, preferable empty directory.

    Note: the makefile contains the sources as inline files.

  2. Download the Meltdown icon and save it as MELTDOWN.ICO in the directory used in step 1.

  3. Download the Spectre icon and save it as SPECTRE.ICO in the directory used in step 1.

  4. Run the following command line to build BTI_RDCL.EXE:

    Note: if necessary, see the MSDN article Use the Microsoft C++ toolset from the command line for an introduction.
    Microsoft (R) Program Maintenance Utility Version 10.00.40219.01
    Copyright (C) Microsoft Corporation.  All rights reserved.
    	RC.EXE /DUNICODE /FoBTI_RDCL.RES /L 0 /N /R /V nm2A7.tmp
    Microsoft (R) Windows (R) Resource Compiler Version 6.1.7600.16385
    Copyright (C) Microsoft Corporation.  All rights reserved.
    Using codepage 1252 as default
    Creating BTI_RDCL.RES
    C:\Program Files\Microsoft Visual Studio 10.0\VC\Include\string.h(54) : warning RC4011: identifier truncated to '_CRT_SECURE_CPP_OVERLOAD_STANDA'
    C:\Program Files\Microsoft Visual Studio 10.0\VC\Include\string.h(76) : warning RC4011: identifier truncated to '_CRT_SECURE_CPP_OVERLOAD_SECURE'
    Writing ICON:1, lang:0x0,       size 9640
    Writing ICON:2, lang:0x0,       size 4264
    Writing ICON:3, lang:0x0,       size 1128
    Writing GROUP_ICON:1,   lang:0x0,       size 48.
    Writing ICON:4, lang:0x0,       size 9640
    Writing ICON:5, lang:0x0,       size 4264
    Writing ICON:6, lang:0x0,       size 1128
    Writing GROUP_ICON:2,   lang:0x0,       size 48.
    Writing 24:1,   lang:0x0,       size 1308.
    Writing VERSION:1,      lang:0x0,       size 1720
    	CL.EXE /Brepro /c /FoBTI_RDCL.OBJ /GA /GF /GS- /Gw /Gy /nologo /O1 /Os /Tcnm2A8.tmp /W4 /we4013 /Zl
    	CL.EXE /Brepro /c /FoBTI_RDCL.TMP /nologo /Tcnm2A9.tmp /W4 /wd4100 /Zl
       Creating library BTI_RDCL.LIB and object BTI_RDCL.exp
    	CERTUTIL.EXE /DecodeHex /F /V nm2AA.tmp BTI_RDCL.DOS
    Input Length = 657
    Output Length = 144
    CertUtil: -decodehex command completed successfully.


If you miss anything here, have additions, comments, corrections, criticism or questions, want to give feedback, hints or tipps, report broken links, bugs, deficiencies, errors, inaccuracies, misrepresentations, omissions, shortcomings, vulnerabilities or weaknesses, …: don’t hesitate to contact me and feel free to ask, comment, criticise, flame, notify or report!

Use the X.509 certificate to send S/MIME encrypted mail.

Note: email in weird format and without a proper sender name is likely to be discarded!

I dislike HTML (and even weirder formats too) in email, I prefer to receive plain text.
I also expect to see your full (real) name as sender, not your nickname.
I abhor top posts and expect inline quotes in replies.

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