Zero-Click Exploit in iPhones

Apple patched an input validation flaw (CVE-2023-41061, CWE-20) in the Wallet component of iOS, iPadOS, and watchOS that can allow arbitrary code execution when a user interacts with a maliciously crafted attachment. The attack is local and requires user interaction (CVSS 7.8, AV:L/UI:R), so the victim must open or act on the crafted attachment — typically delivered through messaging or another application — for the exploit to succeed. A successful attack yields code execution on the device, and media reports describe it as having been used in 'extremely sophisticated attacks' chained with other Apple zero-days. Anyone running iPhone OS (iOS), iPadOS, or watchOS versions prior to iOS/iPadOS 16.6.1 and watchOS 9.6.2 is affected, a population on the order of a billion active devices. Apple disclosed the issue as actively exploited, and CISA added it to the Known Exploited Vulnerabilities (KEV) catalog on 2023-09-11.

Do: Immediately update iPhones and iPads to iOS/iPadOS 16.6.1 or later, and Apple Watch to watchOS 9.6.2 or later. Because the flaw is listed in CISA's KEV catalog and was actively exploited at disclosure, treat patching as urgent for all user fleets, especially high-value targets; until patched, exercise caution with attachments from untrusted sources. No public proof-of-concept is known, but defenders should check fleet OS versions for stragglers on pre-16.6.1 builds.

CVE-2023-41064 is a buffer overflow (CWE-120) in the ImageIO component of Apple iOS, iPadOS, and macOS that is triggered when the system processes a maliciously crafted image. Because ImageIO performs image decoding for messaging and web content, an attacker can reach the flaw through attachments or web pages, and successful exploitation may allow arbitrary code execution on the device. The flaw was exploited in the wild as part of a chain with CVE-2023-41061 (WebKit), which public reporting described as a zero-click, spyware-grade compromise chain used against civil-society targets. All users of iPhones, iPads, and Macs running builds released before Apple's September 2023 fixes are affected, making the exposed population extremely large. The vulnerability was added to the CISA KEV catalog on 2023-09-11, carries a high EPSS score of 45.1% (99th percentile), and no standalone public proof-of-concept is known because exploitation is occurring in real-world attacks rather than labs.

Do: Apply Apple's September 2023 fixes — iOS and iPadOS 16.6.1 or later and macOS Ventura 13.5.2 or later — across all iPhone, iPad, and Mac fleets, which satisfies the CISA KEV required action. Because the observed in-the-wild chain paired this ImageIO bug with the CVE-2023-41061 WebKit flaw, treat unpatched devices as actively targeted and prioritize high-value users and privileged endpoints. If updates cannot be deployed promptly, follow the KEV guidance to apply vendor mitigations or discontinue use of the affected devices.