Apple says all of its Mac and iOS devices are vulnerable to hackers, after revelations there are two major flaws in nearly all computer chips made in the past decade.

The tech giant said it would release a patch for the Safari web browser on its iPhones, iPads and Macs within days.

This week Alphabet Inc's Google and other security researchers disclosed two major chip flaws — one called Meltdown affecting only Intel Corp chips, and one called Spectre affecting nearly all computer chips made in the past decade.

Apple said all Mac and iOS devices were affected by both Meltdown and Spectre.

But the most recent operating system updates for Mac computers, Apple TVs, iPhones and iPads protect users against the Meltdown attack and do not slow down the devices, it added, and Meltdown does not affect the Apple Watch.

Macs and iOS devices are vulnerable to Spectre attacks through code that can run in web browsers.

Your mobile phone is collecting data about you all the time and online personal assistants like Siri are making things worse.
Shortly after the researchers disclosed the chip flaws, Google and Microsoft Corp released statements telling users which of their products were affected.

Google said its users of Android phones — more than 80 per cent of the global market — were protected if they had the latest security updates.

Apple remained silent for more than a day about the fate of the hundreds of millions of users of its iPhones and iPads.

Ben Johnson, co-founder and chief strategist for cyber security firm Carbon Black, said the delay in updating customers about whether Apple's devices are at risk could affect Apple's drive to get more business customers to adopt its hardware.

"Something this severe gets the attention of all the employees and executives at a company, and when they go asking the IT and security people about it and security doesn't have an answer for iPhones and iPads, it just doesn't give a whole lot of confidence," Mr Johnson said.

The news of the Meltdown and Spectre flaws sparked a sell-off in Intel's stock as investors tried to gauge the costs to the chipmaker.