CVE-2025-31203 is an integer overflow vulnerability identified in Apple’s iOS and iPadOS platforms, as well as other Apple operating systems including macOS Sequoia, macOS Sonoma, tvOS, visionOS, and watchOS. The root cause is insufficient input validation that allows an attacker on the same local network segment to trigger an integer overflow, leading to a denial-of-service (DoS) condition. This vulnerability does not require any privileges or user interaction, making it easier to exploit for anyone with local network access. The integer overflow is classified under CWE-190, indicating improper handling of numeric values that exceed their storage capacity. Apple has addressed this issue by improving input validation in iOS 18.4, iPadOS 18.4, and other corresponding OS updates. The vulnerability affects availability only, with no impact on confidentiality or integrity. The CVSS v3.1 base score is 6.5, indicating a medium severity level. The attack vector is local network (AV:A), with low attack complexity (AC:L), no privileges required (PR:N), and no user interaction needed (UI:N). No known exploits have been reported in the wild, but the potential for denial-of-service attacks remains a concern, especially in environments where attackers can gain local network access. The vulnerability’s scope is limited to Apple devices running vulnerable OS versions, emphasizing the importance of timely patching.

The primary impact of CVE-2025-31203 is the potential for denial-of-service attacks against Apple devices running vulnerable versions of iOS, iPadOS, and related operating systems. An attacker with local network access can exploit this vulnerability to crash or disrupt device operation, potentially causing service interruptions for end users. This can affect individual users, enterprise environments, and service providers relying on Apple devices for critical communications or operations. The lack of confidentiality or integrity impact reduces the risk of data breaches or unauthorized data manipulation, but availability disruption can still have significant operational consequences. In enterprise or public Wi-Fi environments, attackers could leverage this flaw to degrade network reliability or disrupt business continuity. The absence of required privileges and user interaction lowers the barrier to exploitation, increasing the likelihood of opportunistic attacks in unsecured or poorly segmented networks. However, the need for local network access limits remote exploitation, reducing the overall attack surface compared to internet-facing vulnerabilities.

To mitigate CVE-2025-31203, organizations and users should promptly apply the security updates released by Apple, including iOS 18.4, iPadOS 18.4, iPadOS 17.7.6, macOS Sequoia 15.4, macOS Sonoma 14.7.5, tvOS 18.4, visionOS 2.4, and watchOS 11.4. Beyond patching, network segmentation should be enforced to limit local network exposure, especially in enterprise and public Wi-Fi environments. Implementing strong network access controls, such as client isolation on Wi-Fi networks, can reduce the risk of local attackers reaching vulnerable devices. Monitoring network traffic for unusual patterns or repeated connection attempts may help detect exploitation attempts. Organizations should also educate users about the risks of connecting to untrusted networks and encourage the use of VPNs to protect device communications. Regular vulnerability scanning and asset inventory management will help identify devices running outdated OS versions. Finally, consider deploying intrusion detection/prevention systems (IDS/IPS) tuned to detect anomalous network behavior associated with DoS attempts targeting Apple devices.