If you haven’t already heard about Meltdown and Spectre, it is a vulnerability that will affect almost every computer. If your tech is out of date, you are more likely to be affected. However, if you keep everything up to date, you will be fine. Below you can find some more details on the vulnerability and how you can protect yourself from Meltdown and Spectre Ubuntu and other operating systems are getting affected by.
What are Meltdown and Spectre?
These vulnerabilities are complex and to fully understand how they have come about, you will need to understand the process called speculative execution. This process is used by the chips in your tech to allow the processors to run as they should. In the simplest way, it basically guesses what might come next and work ahead in order to keep the process running smoothly. It is almost preparing the computer for the next task that might happen.
This is where Meltdown and Spectre come into play. They use the speculative execution to essentially do something it shouldn’t. The even scarier thing is that there are actually three vulnerabilities between them.
What Can They Be Used For?
The end goal of using these vulnerabilities would be to gain access to the target machine/machines.
Spectre would involve the use of a single program. The chosen program, most likely a web browser, would become compromised and then be used to access other programs.
The Meltdown vulnerability is one that allows attackers to gain access to the computer’s memory. However, it allows access to a part of the memory that is not meant to be accessible.
What Can You Do (Non-Ubuntu User)?
The main way of combatting these vulnerabilities is to keep your tech up to date. Companies are regularly pushing out updates that patch this kind of vulnerability.
Apple has recently released an iOS and MacOS patch that protects users against Meltdown and Spectre. Other companies have also released updates or alternatively, a way to patch the vulnerabilities yourself.
So, if you are sitting on an older version of Windows, Android, iOS etc. then it is a key requirement to update the machine as soon as possible to prevent your devices from being hacked.
How to Patch Meltdown and Spectre on Ubuntu
In some cases, you may have already run this patch already. However, it is always good to check so in person. This is how you check:
Run the following command:
grep –i isolation /var/log/kern.log
If you receive an output similar to the following, the vulnerability has been patched:
[0.000000]! Kernel/User page tables isolation: enabled
If you have run the grep command and you have failed to find the output similar to the one above, you will have to update the system manually using the steps below:
Run the following commands in order:
sudo apt-get update
sudo apt-get install linux-generic intel-microcode
After running these, you will need to reboot the server:
sudo shutdown –r now
After your machine has booted back up, run the next command:
dmesg | grep “kernel/user page tables isolation: enabled”
Now that you have run the above commands, you should receive an output similar to the one mentioned above. Your Ubuntu machine will now be updated, and the vulnerabilities will be patched.
Vulnerabilities that can gain access to the machine’s core are scary. You wouldn’t expect it to be possible, but every day new bugs are being found and used to gain access to machines etc. However, keeping up to date will prevent the possibility of being hacked.
