Apple patches new zero-day bug used to hack iPhones and Macs

Apple has released security updates to fix a zero-day vulnerability exploited in the wild by attackers to hack into iPhones and Macs running older iOS and macOS versions.

The zero-day patched today (tracked as CVE-2021-30869) [1, 2] was found in the XNU operating system kernel and was reported by Erye Hernandez and Clément Lecigne of Google Threat Analysis Group, and Ian Beer of Google Project Zero.

Successful exploitation of this bug leads to arbitrary code execution with kernel privileges on compromised devices.

"Apple is aware of a report that this issue may have been actively exploited," Apple said when describing the zero-day bug.

The complete list of impacted devices includes:

• iPhone 5s, iPhone 6, iPhone 6 Plus, iPad Air, iPad mini 2, iPad mini 3, and iPod touch (6th generation) running iOS 12.5.5
• and Macs with Security Update 2021-006 Catalina.

Apple also backported security updates for two previously patched zero-days, one of them reported by The Citizen Lab and used to deploy NSO Pegasus spyware on hacked devices. 

0day privilege escalation for macOS Catalina discovered in the wild by @eryeh https://t.co/yvCWPo45fL

We saw this used in conjunction with a N-day remote code execution targeting webkit.

Thanks to Apple for getting patch out so quickly.

— Shane Huntley (@ShaneHuntley) September 23, 2021

Long stream of zero-days exploited in the wild

Besides today's zero-day, Apple had to deal with what looks like an unending stream of zero-day bugs used in attacks targeting iOS and macOS devices:

• two zero-days earlier this month, one of them used also used to install Pegasus spyware on iPhones,
• the FORCEDENTRY exploit disclosed in August (previously tracked by Amnesty Tech as Megalodon),
• three iOS zero-days (CVE-2021-1870, CVE-2021-1871, CVE-2021-1872) in February, exploited in the wild and reported by anonymous researchers,
• an iOS zero-day (CVE-2021-1879) in March that may have also been actively exploited,
• one zero-day in iOS (CVE-2021-30661) and one in macOS (CVE-2021-30657) in April, exploited by Shlayer malware,
• three other iOS zero-days (CVE-2021-30663, CVE-2021-30665, and CVE-2021-30666) in May, bugs allowing for arbitrary remote code execution (RCE) simply by visiting malicious websites,
• a macOS zero-day (CVE-2021-30713) in May, which was abused by the XCSSET malware to bypass Apple's TCC privacy protection,
• two iOS zero-day bugs (CVE-2021-30761 and CVE-2021-30762) in June that "may have been actively exploited" to hack into older iPhone, iPad, and iPod devices.

Update: A previous version of the story said Apple fixed three zero-days, one of them used to deploy spyware. We have updated the story to correctly say the company patched a single zero-day exploited in the wild.