Meltdown & Spectre Vulnerabilities – Security Update & Anti-Virus Compatibility

Read time 4 mins

Written January 2018

Now that the media hysteria appears to have calmed down, we’ve all been able to focus on the core facts surrounding the published Meltdown and Spectre vulnerabilities.

At this point the UK’s National Cyber Security Centre (NCSC) are still stating that there is no evidence that the vulnerabilities are currently being exploited, as that any potential exploit would also need to be combined with an additional local or remote code execution vulnerability to be able to access locally held information on a device – which itself would also need to circumvent security anti-virus safeguards to be successful.

As communicated yesterday, Microsoft have now released a security update for the impacted Windows operating systems, however there are stability and compatibility concerns with a number of anti-virus software applications. The compatibility issue is caused when anti-virus applications make unsupported calls into Windows kernel memory. These calls may cause stop errors (also known as blue screen errors) that make the device unable to boot. To help prevent stop errors caused by incompatible anti-virus applications, Microsoft is only offering the Windows security updates released on January 3, 2018 to devices running anti-virus software from partners who have confirmed their software is compatible with the January 2018 Windows operating system security update and have the necessary registry key (flag) set.

Please find below the current anti-virus compatibility list (updated information as of 11th January 2018 at 22:23 GMT)

 

Compatible AND Sets Registry Key

 

Compatible but DOES NOT YET Set Registry Key

 

NOT YET Compatible

Key Guidance For Multi-Customer Virtual Environments

The key guidance at present is that if you are hosting a multi-customer virtual environment (e.g. Microsoft Azure, Google Cloud Platform, Amazon etc) then you need to deploy the update to the physical hosts (hypervisors) ASAP to avoid potential cross-customer data leakage. This was the reason behind the experienced outages yesterday for any Microsoft Azure customer, and why Google and Amazon have rapidly deployed the updates.

Users Running Rogue Software

If you are running an environment where end users could potentially be allowed to run “rogue” software without any protection, then you should also consider an early deployment of the updates – although this practice should be discouraged, or further protections put in place.

Otherwise the normal patching schedule (aka ‘patch Tuesday’) seems perfectly reasonable, ensuring though that the caveats relating to anti-virus application adoption and compatibility have been followed. This ensures that the updates follow your standard deployment methodology as the likelihood of business impact from device instability is far higher than the Meltdown vulnerability being exploited at this point.

Apple Update

Apple have now officially confirmed that all Mac systems and iOS devices are affected, but there are no known exploits impacting customers at this time. Apple has already released mitigations in iOS 11.2, macOS 10.13.2, and tvOS 11.2 to help defend against Meltdown. In the coming days Apple plan to release mitigations in Safari to help defend against Spectre. The Apple Watch is not affected by Meltdown.

Maintain Good Practice

As always, a key aspect here is to ensure that your security products are all up to date on both end-user and server platforms (which Littlefish will continue to manage on our customers’ behalf (for supported devices)) and that your users remain vigilant when receiving emails or web browsing. Littlefish are also tracking the situation with the anti-virus vendors (see above) to ensure that environments are ready for the scheduled updates next week.

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