Restricting admin rights heavily mitigates impact of Microsoft flaws

Microsoft fixed 1,268 vulnerabilities across its products during 2020, representing a massive 48% rise against reported flaws the previous year and a 181% surge in flaws since 2016.

While remote code execution exploits were still highly prevalent, the most common attack last year involved exploiting elevation of privilege flaws, with 559 vulnerabilities compared to 345 for remote code execution.

Vulnerabilities in this camp trebled over 2020 and accounted for 44% of all Microsoft flaws, according to Beyond Trust, while 56% of all critical flaws may have been mitigated by simply removing admin rights from endpoints.

“The huge jump in the number of vulnerabilities tells me that more and more security researchers are actively helping companies to protect themselves, but sadly also that the bad guys are doing the same to actively search for the vulnerabilities,” said Microsoft MVP and ethical hacker, Sami Laiho.

“There were numerous zero-day vulnerabilities in multiple different products last year and that means that proactive measures are even more important than ever before.

“The removal of admin rights is a great proactive protection, as you can see from the numbers in this report. We need to protect the components that execute malicious payloads, so our most important apps to protect are things that browse the web or read email.”

Beyond Trust’s annual report examined all flaws that Microsoft discloses throughout the last year affecting a series of its products including Windows, its web browsers, its Office productivity suite, and Windows Server.

Its release also coincides at a time businesses are reeling from a set of Microsoft Exchange Server flaws that have been actively exploited by Chinese state-backed hackers.

The number of flaws in Windows surged last year to 907, with Beyond Trust claiming that removing admin rights would've 70% of these. Similarly, Windows Server users will have encountered 902 flaws, with 66% of these potentially mitigated by restricting privileges. Both products reported considerably more vulnerabilities in 2020 than the previous year.

Despite the powerful way in which restricting privileges can mitigate attacks, however, patching the vulnerabilities in the first place, when fixes are available, remains the best way to reduce risk.

The report claimed, however, that although may organisations understand the need to install security patches immediately upon release, the volume can be overwhelming at times.

For example, last year there were at least a couple of occasions when hundreds of patches from various vendors were released all at once - creating a ‘Fujiwhara effect’.

Beyond Trust’s report added that the reality is many companies are often under-resourced from an IT perspective and struggle with timely patching every critical flaw they encounter across their products.