CVE-2023-42916 is a vulnerability classified under CWE-125 (Out-of-bounds Read) affecting Apple Safari browser and underlying OS components on iOS, iPadOS, and macOS. The flaw arises from improper input validation when processing web content, allowing an attacker to craft malicious web pages that trigger out-of-bounds memory reads. This can lead to unauthorized disclosure of sensitive information from memory, potentially exposing user data or browser internals. The vulnerability requires no privileges or authentication but does require user interaction, such as visiting a malicious or compromised website. Apple has fixed the issue in iOS 17.1.2, iPadOS 17.1.2, macOS Sonoma 14.1.2, and Safari 17.1.2 by improving input validation to prevent out-of-bounds reads. The CVSS v3.1 base score is 6.5 (medium), reflecting network attack vector, low attack complexity, no privileges required, user interaction needed, and high impact on confidentiality but no impact on integrity or availability. Although Apple is aware of reports of exploitation in the wild against versions before iOS 16.7.1, no widespread campaigns have been documented. The vulnerability primarily threatens confidentiality by leaking sensitive information to attackers who lure users to malicious web content.

For European organizations, the primary impact is the potential leakage of sensitive information through Safari on Apple devices running vulnerable OS versions. This could include exposure of personal data, session tokens, or other confidential information held in memory during web browsing. Such data leakage can facilitate further attacks like account takeover or espionage. Organizations relying heavily on Apple devices, especially in sectors handling sensitive or regulated data (finance, healthcare, government), face increased risk. The vulnerability does not affect system integrity or availability, so direct disruption is unlikely. However, the confidentiality breach could lead to compliance violations under GDPR if personal data is exposed. The requirement for user interaction means phishing or social engineering campaigns could be used to exploit this vulnerability, increasing risk in environments with less user security awareness.

European organizations should prioritize updating all Apple devices to iOS 17.1.2, iPadOS 17.1.2, macOS Sonoma 14.1.2, and Safari 17.1.2 or later to remediate the vulnerability. Where immediate patching is not feasible, organizations should implement network-level protections such as web filtering to block access to known malicious sites and employ DNS filtering services to reduce exposure to malicious web content. User education campaigns should emphasize the risks of clicking unknown or suspicious links, especially on Apple devices. Security teams should monitor for phishing attempts that could exploit this vulnerability. Additionally, deploying endpoint detection and response (EDR) solutions capable of detecting anomalous browser behavior may help identify exploitation attempts. Organizations should audit their device inventories to identify unpatched Apple devices and enforce patch management policies. Finally, consider restricting Safari usage or enforcing alternative browsers with different rendering engines in high-risk environments until patches are applied.