CVE-2025-43402 is a memory corruption vulnerability in Apple macOS identified as CWE-787, which typically involves out-of-bounds writes or buffer overflows. This flaw allows a local application with low privileges to manipulate memory improperly, potentially causing unexpected system termination (crashes) or corruption of process memory. The vulnerability affects multiple macOS versions prior to the patched releases: Sequoia 15.7.4, Sonoma 14.8.4, and Tahoe 26.1. The root cause lies in insufficient memory handling safeguards within the affected macOS components, enabling an attacker to exploit this flaw without requiring user interaction. The CVSS v3.1 score of 7.8 indicates a high severity, with the vector showing local attack vector (AV:L), low attack complexity (AC:L), low privileges required (PR:L), no user interaction (UI:N), unchanged scope (S:U), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). Although no exploits have been reported in the wild, the vulnerability presents a significant risk for denial of service and potential privilege escalation or code execution scenarios if combined with other vulnerabilities. The fix involves improved memory handling implemented in the specified macOS updates.

The vulnerability can lead to unexpected system crashes, causing denial of service for users and critical applications. Memory corruption may allow attackers to manipulate process memory, potentially leading to privilege escalation or arbitrary code execution if chained with other vulnerabilities. This threatens the confidentiality, integrity, and availability of affected systems. Organizations relying on macOS for critical infrastructure, development, or operational environments could face operational disruptions and increased risk of compromise. The requirement for local access and low privileges means insider threats or malware already on the system could exploit this vulnerability to escalate privileges or destabilize the system. The absence of user interaction lowers the barrier for exploitation once local access is obtained. Overall, the impact is significant for organizations with macOS deployments, especially where system stability and security are paramount.

1. Apply the official patches by upgrading to macOS Sequoia 15.7.4, Sonoma 14.8.4, or Tahoe 26.1 immediately to remediate the vulnerability. 2. Restrict local application execution privileges by enforcing strict application whitelisting and sandboxing policies to limit the ability of untrusted apps to run. 3. Employ endpoint detection and response (EDR) solutions to monitor for anomalous process behavior indicative of exploitation attempts, such as unexpected crashes or memory corruption patterns. 4. Limit local user privileges and avoid granting unnecessary administrative rights to reduce the attack surface. 5. Conduct regular audits of installed applications and remove or isolate any untrusted or unnecessary software. 6. Educate users about the risks of running unverified local applications and enforce policies to prevent unauthorized software installation. 7. Maintain comprehensive backups and incident response plans to quickly recover from potential system disruptions caused by exploitation.