CVE-2022-42856

CVE-2022-42856 is a type confusion vulnerability (CWE-843) in Apple's WebKit web engine, addressed with improved state handling and affecting Safari, iPhone OS (iOS), iPadOS, macOS (Ventura) and tvOS. It is triggered when a user processes maliciously crafted web content, for example by visiting an attacker-controlled web page, in a WebKit-based browser or app. Successful exploitation may lead to arbitrary code execution on the affected device. Anyone running the affected Apple platforms below the December 2022 patch level (Safari 16.2, macOS Ventura 13.1, tvOS 16.2, iOS/iPadOS 15.7.2, iOS 16.1.2) was exposed, which effectively means most Apple users at the time of disclosure. Exploitation is confirmed: Apple reported the issue may have been actively exploited against iOS versions released before iOS 15.1, it was added to CISA KEV on 2022-12-14 (EPSS 8.5%, 95th percentile), and related reporting ties it to commercial spyware campaigns in Italy, Malaysia, Kazakhstan and the UAE.

What to do: Update immediately to Safari 16.2, macOS Ventura 13.1, tvOS 16.2, and iOS/iPadOS 15.7.2 (for iOS 15-era devices) or iOS 16.1.2 (for iOS 16-era devices), or any later release; this is a CISA KEV entry whose required action is to apply vendor updates. Because the flaw was exploited as a zero-day against iOS versions before iOS 15.1 and is linked to commercial spyware campaigns, treat patching as urgent and verify that all managed and BYOD iPhones and iPads are on a fixed version; on iOS, all third-party browsers and most web-content apps use WebKit, so the OS update itself is the remediation rather than switching browsers.