Apple addressed a third zero

CVE-2022-22587 is a memory corruption flaw (CWE-787, out-of-bounds write) in Apple's operating systems that Apple addressed with improved input validation. It is triggered by a malicious application already running on a vulnerable device, which can exploit the corruption to execute arbitrary code with kernel privileges — the highest privilege level of the OS. All iPhones and iPads running iOS/iPadOS versions earlier than 15.3 and Macs running macOS Monterey earlier than 12.2 or Big Sur earlier than 11.6.3 are affected. Apple reported the issue as actively exploited, and CISA added it to the Known Exploited Vulnerabilities catalog on 2022-01-28; EPSS rates it at 11.6% probability of exploitation in the next 30 days (96th percentile). It was one of two actively exploited Apple zero-days patched in Apple's January 2022 emergency updates.

Do: Update iPhones and iPads to iOS/iPadOS 15.3 and Macs to macOS Monterey 12.2 or Big Sur 11.6.3 (or later). Inventory managed fleets for devices below these versions, since the flaw is exploited in the wild and CISA KEV requires applying vendor updates. Until devices are patched, limit exposure by avoiding installation of untrusted applications on vulnerable iPhones, iPads, and Macs.

A cross-origin issue in the IndexDB API was addressed with improved input validation. This issue is fixed in iOS 15.3 and iPadOS 15.3, watchOS 8.4, tvOS 15.3, Safari 15.3, macOS Monterey 12.2. A website may be able to track sensitive user information.

CVE-2022-22620 is a use-after-free (CWE-416) in Apple's WebKit browser engine, the component that renders web content on iPhones, iPads, Macs, and Safari. An attacker triggers it by getting a victim to process maliciously crafted web content, such as visiting an attacker-controlled webpage, requiring no privileges and only user interaction with the content. Successful exploitation may lead to arbitrary code execution in the context of the browser, with high impact on confidentiality, integrity, and availability (CVSS 3.1: 8.8 High). All devices running iOS or iPadOS before 15.3.1, macOS Monterey before 12.2.1, or Safari before 15.3 are affected, which effectively means the broad Apple user base at the time of disclosure. Apple reported the issue may have been actively exploited in the wild; it was added to CISA's Known Exploited Vulnerabilities catalog on 2022-02-11 and carries a 16.2% EPSS probability of exploitation in the next 30 days (97th percentile).

Do: Update iPhones and iPads to iOS/iPadOS 15.3.1, Macs to macOS Monterey 12.2.1, and Safari to version 15.3 (builds 16612.4.9.1.8 or 15612.4.9.1.8), per Apple's vendor instructions. Inventory for devices still on pre-patch versions, prioritizing user workstations and mobile devices that browse web or HTML email content, since WebKit loads content automatically. Note the vulnerability is listed in CISA's KEV catalog with 'apply updates per vendor instructions' as the required action, so patching is the only reliable mitigation.