CVE-2025-43348 is a logic flaw in Apple macOS's Gatekeeper security mechanism, which is responsible for verifying the authenticity and integrity of applications before allowing them to run. Gatekeeper typically prevents untrusted or malicious software from executing by enforcing signature checks and developer validations. The vulnerability stems from an improper validation process within Gatekeeper, enabling an app to bypass these security checks. This means that a malicious or unsigned application could potentially run on a macOS system without triggering Gatekeeper's protections. Apple has resolved this issue in macOS Sonoma 14.8.2 and macOS Sequoia 15.7.2 by improving the validation logic. The affected versions are unspecified but include all versions prior to these patches. There are no known exploits in the wild at the time of publication, but the flaw presents a significant risk as it undermines a core macOS security control. Attackers could leverage this bypass to install malware, execute unauthorized code, or persist on systems undetected. The vulnerability does not require user interaction beyond app execution, and no authentication is needed to exploit it, increasing its risk profile. The absence of a CVSS score necessitates a severity assessment based on impact and exploitability factors.

For European organizations, this vulnerability poses a substantial risk, especially those with macOS endpoints in their IT environment. By bypassing Gatekeeper, attackers can deploy malware or unauthorized applications that evade initial security checks, potentially leading to data breaches, espionage, or ransomware infections. The integrity and confidentiality of sensitive corporate data could be compromised if malicious code gains execution privileges. Availability could also be affected if attackers deploy disruptive payloads. The risk is heightened in sectors with high macOS usage such as technology, creative industries, finance, and government agencies. Additionally, organizations relying on Gatekeeper as a primary defense mechanism may find their endpoint security posture weakened until patches are applied. The lack of known exploits in the wild suggests a window of opportunity for proactive defense, but also the possibility of future targeted attacks. The impact is amplified in environments where patch management is slow or where users have administrative privileges, facilitating easier exploitation.

European organizations should immediately prioritize updating all macOS devices to at least macOS Sonoma 14.8.2 or macOS Sequoia 15.7.2 to remediate the vulnerability. Beyond patching, organizations should implement strict application whitelisting policies to restrict execution to approved software only. Endpoint detection and response (EDR) solutions should be configured to monitor for unusual application behaviors indicative of Gatekeeper bypass attempts. User education campaigns should reinforce caution when executing unknown or untrusted applications. Network segmentation can limit lateral movement if a device is compromised. Additionally, organizations should audit existing macOS systems for unauthorized or unsigned applications that may have bypassed Gatekeeper prior to patching. Regular vulnerability scanning and compliance checks should include verification of macOS versions to ensure timely patch deployment. Finally, consider deploying additional macOS security tools that provide layered defenses beyond Gatekeeper.