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Intel AMT, continued

Matthew Garrett has a new tool to check for AMT on Linux:

If AMT is enabled and provisioned and the AMT version is between 6.0 and 11.2, and you have not upgraded your firmware, you are vulnerable to CVE-2017-5689. Disable AMT in your system firmware.

https://github.com/mjg59/mei-amt-check

A little bird told me some info about Intel AMT and Linux:

* Some BMC/IPMI devices also listen on port 623 because they support the same asf-rmcp protocol. So if you are using nmap to scan networks you may see false positives from these devices.

* The Intel OpenAMT tool can be used on Linux to determine if AMT is enabled. The procedure is something like:
  * build with: ./configure;make
  * on the system to test, load the mei modules with: modprobe mei-me
  * run the src/lms binary (only uses standard libraries, no need to ‘make install’)
  * check daemon.log, not enabled should be something like “LMS: Cannot connect to Intel AMT via MEI driver”
  * clean up by killing the running lms process, removing the lms binary, and unloading the mei modules: rmmod mei-me mei
https://sourceforge.net/projects/openamt/

* On Linux, blacklisting the mei-me/mei modules will prevent local access to AMT, but doesn’t help if it’s already enabled.

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Matthew Garrett leaves CoreOS, joins Google

Matthew Garrett is leaving CoreOS and has gone to Google!

https://coreos.com/blog/working-on-container-linux.html

 

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Linux Kernel lockdown

David Howells of Red Hat submitted a 16-part patch to the Linux-(Security,EFI,Kernel) mailing lists, with an interesting security patch for the Linux kenel. The patch includes contributions from: David Howells, Josh Boyer, Kyle McMartin, Matthew Garrett, and Dave Young. Quoting the patch announcement:

These patches provide a facility by which a variety of avenues by which userspace can feasibly modify the running kernel image can be locked down. These include:

* No unsigned modules and no modules for which can’t validate the signature.
* No use of ioperm(), iopl() and no writing to /dev/port.
* No writing to /dev/mem or /dev/kmem.
* No hibernation.
* Restrict PCI BAR access.
* Restrict MSR access.
* No kexec_load().
* Certain ACPI restrictions.
* Restrict debugfs interface to ASUS WMI.

The lock-down can be configured to be triggered by the EFI secure boot status, provided the shim isn’t insecure.  The lock-down can be lifted by typing SysRq+x on a keyboard attached to the system. They are dependent for some EFI definitions on the keys-uefi branch.

Copy secure_boot flag in boot params across kexec reboot
Add the ability to lock down access to the running kernel image
efi: Get the secure boot status
efi: Lock down the kernel if booted in secure boot mode
efi: Disable secure boot if shim is in insecure mode
efi: Add EFI_SECURE_BOOT bit
hibernate: Disable when the kernel is locked down
acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
Add a sysrq option to exit secure boot mode
kexec: Disable at runtime if the kernel is locked down
PCI: Lock down BAR access when the kernel is locked down
x86: Lock down IO port access when the kernel is locked down
ACPI: Limit access to custom_method when the kernel is locked down
asus-wmi: Restrict debugfs interface when the kernel is locked down
Restrict /dev/mem and /dev/kmem when the kernel is locked down
x86: Restrict MSR access when the kernel is locked down

More information:
http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=keys-lockdown
http://vger.kernel.org/majordomo-info.html

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Matthew and James on IoT security

Matthew Garret and James Bottomley have two blog posts out on IoT security.

I have nearly given up on IoT security, there is so much new IoT vulnerabilities in the news each day. 😦

http://mjg59.dreamwidth.org/45098.html

Home Automation: Coping with Insecurity in the IoT

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Matthew Garrett on Linux boot security

Amber Ankerholz wrote an article for Linux.com on the Linux boot-time security presentation that Matthew Garrett recently gave at the Linux Security Summit. In addition to the article, the video of the presentation is also available.

https://www.linux.com/news/matthew-garrett-explains-how-increase-security-boot-time

 

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Purism announces advisory board

Purism announces advisory board, and one of the members is Linux firmware security expert Matthew Garrett, which is good news:

http://www.prweb.com/releases/2016/09/prweb13650532.htm

 

 

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