Meltdown, Spectre and your APs
2018 has started off interestingly to say the least. A new duo of major security flaws has been announced. These exploits, Meltdown and Spectre, take advantage of aspects of your CPUs to leak sensitive data.
According to the techies who found the flaws, the cause of this is a performance feature that’s called ‘Speculative Execution’, present on most processors.
What does it mean you ask? It’s a feature that optimises performance by guessing which path of operation will be taken next, if the guess is wrong, then the execution is invalidated. The issue here is that the feature needs to access a portion of privileged kernel memory, which is supposed to be protected.
Malicious programs could access that protected kernel memory, in which password, encrypted data and other sensitive info are stored.
This can sound quite scary, but here it the catch — whoever wants to exploit this, needs to have access to the machine and install the malicious code.
Spectre — also known as CVE-2017–5753 and CVE-2017–5715
This exploit breaks down the isolation between different applications, which allows an attacker to trick error free programs to give out their secrets.
Meltdown — This flaw breaks the isolation between user apps and OS (Melting the barriers) which allows a program to access memory content, which stores your OS secrets.
What’s next?
Most Major OS have already released patches to mitigate this, although some initial results have shown that this will also increase the CPU load up to 30%. In our own server farm, we’ve seen an increase of about 11% on average.
Why are we talking about this?
Although is useful info, this is also affecting the CPU on Routers and APs, which means we need to look into this. As we are using LEDE as our base firmware, we’re now monitoring it closely. Once the kernel patches are merged, we’ll start testing things out to assess what the performance impacts are.
Like we’ve mentioned earlier, the attacker needs to have access to the AP/Router in order to execute this code. If someone does get access to your Access Point, he will already have access to most of the data on the AP, which makes running this exploit pointless.
And just as a final comment of reassurance, client confidential data is not stored on the device at any point. In terms of real world impact for your APs, the only possible effect your APs should take from this is a potential performance impact once a fix is issued.
You can read more about both of the exploits here:
https://meltdownattack.com/
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