Two severe vulnerabilities have been discovered in Intel chips, either of which could enable attackers to seize sensitive information from apps by accessing the core memory. The first vulnerability, Meltdown, can effectively remove the barrier between user applications and sensitive parts of the operating system. The second vulnerability, Spectre, also found in AMD and ARM chips, can trick vulnerable applications into leaking their memory contents.
Applications installed on a device generally run in “user mode,” away from the more sensitive parts of the operating system. If an app needs access to a sensitive area, for example the underlying disk, network, or processing unit, it needs to ask permission to use “protected mode.” In Meltdown’s case, an attacker could access protected mode and the core memory without requiring permission, effectively removing that barrier — and enabling them to potentially steal data from the memory of running apps, such as data from password managers, browsers, e-mails, and photos and documents.
— Michael Schwarz (@misc0110) January 4, 2018
Meltdown and Spectre are hardware bugs, so patching can be quite tricky. Patches against Meltdown have been issued for Linux, Windows, and MacOS, but work is still on the way to harden applications against Spectre. You can find more information here.
In the meantime it is important, as