Spectre and Meltdown on AWS

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nan008
Posts: 2
Joined: 2018/03/09 15:13:19

Spectre and Meltdown on AWS

Post by nan008 » 2018/03/09 15:23:40

Hello,

I am running Centos 7.4.1708 on AWS VMs and because Spectre/Meltdown is in a panic stage for patching, we upgraded our servers to the new kernel and microcode, yet still the test I am running is indicating that I am not 100% secure. I know Amazon aready applied the patches to AWS hypervisors, so why I am getting this (Variant 2 most worrying for us)

running

CentOS Linux 7 x86_64 HVM EBS 1708_11.01
Kernel .10.0-693.21.1


result:

* Hardware support (CPU microcode) for mitigation techniques
* Indirect Branch Restricted Speculation (IBRS)
* SPEC_CTRL MSR is available: NO
* CPU indicates IBRS capability: NO
* Indirect Branch Prediction Barrier (IBPB)
* PRED_CMD MSR is available: NO
* CPU indicates IBPB capability: NO
* Single Thread Indirect Branch Predictors (STIBP)
* SPEC_CTRL MSR is available: NO
* CPU indicates STIBP capability: NO
* Enhanced IBRS (IBRS_ALL)
* CPU indicates ARCH_CAPABILITIES MSR availability: NO
* ARCH_CAPABILITIES MSR advertises IBRS_ALL capability: NO
* CPU explicitly indicates not being vulnerable to Meltdown (RDCL_NO): NO
* CPU microcode is known to cause stability problems: NO (model 85 stepping 4 ucode 0x200003a)
* CPU vulnerability to the three speculative execution attacks variants
* Vulnerable to Variant 1: YES
* Vulnerable to Variant 2: YES
* Vulnerable to Variant 3: YES

CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'
* Mitigated according to the /sys interface: YES (kernel confirms that the mitigation is active)
* Kernel has array_index_mask_nospec: UNKNOWN (missing 'perl' binary, please install it)
* Kernel has the Red Hat/Ubuntu patch: YES
> STATUS: NOT VULNERABLE (Mitigation: Load fences)

CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'
* Mitigated according to the /sys interface: NO (kernel confirms your system is vulnerable)
* Mitigation 1
* Kernel is compiled with IBRS/IBPB support: YES
* Currently enabled features
* IBRS enabled for Kernel space: NO
* IBRS enabled for User space: NO
* IBPB enabled: NO
* Mitigation 2
* Kernel compiled with retpoline option: YES
* Kernel compiled with a retpoline-aware compiler: UNKNOWN
> STATUS: VULNERABLE (Vulnerable: Retpoline without IBPB)

CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'
* Mitigated according to the /sys interface: YES (kernel confirms that the mitigation is active)
* Kernel supports Page Table Isolation (PTI): YES
* PTI enabled and active: YES
* Running as a Xen PV DomU: NO
> STATUS: NOT VULNERABLE (Mitigation: PTI)


Anyone can shed some light on this?

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TrevorH
Site Admin
Posts: 33202
Joined: 2009/09/24 10:40:56
Location: Brighton, UK

Re: Spectre and Meltdown on AWS

Post by TrevorH » 2018/03/09 16:19:41

Variant 2 needs microcode support to fix it.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

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