CVE-2025-43185 is a medium-severity vulnerability affecting Apple macOS, specifically addressed in macOS Sequoia 15.6. The vulnerability stems from a downgrade issue related to code-signing restrictions. Code-signing is a security mechanism used by Apple to ensure that only trusted and verified applications can run with certain privileges or access protected resources. In this case, the downgrade issue allowed an application to bypass or weaken these code-signing restrictions, potentially enabling it to access protected user data without proper authorization. The vulnerability does not require privileges (PR:N) but does require user interaction (UI:R), such as the user launching or interacting with the malicious app. The attack vector is local (AV:L), meaning the attacker must have local access to the system, for example by tricking the user into installing or running a malicious app. The impact is primarily on confidentiality (C:H), allowing unauthorized access to sensitive user data, but it does not affect integrity or availability. The vulnerability is related to CWE-347, which involves improper verification of cryptographic signatures, indicating that the downgrade attack allowed bypassing signature verification. No known exploits are currently reported in the wild, and no specific affected macOS versions are listed beyond the fix being in 15.6. This suggests that earlier versions prior to 15.6 are vulnerable. The vulnerability highlights the risk of downgrade attacks where security controls are weakened by forcing the system to accept older, less secure versions or configurations of code-signing policies. Overall, this vulnerability could allow malicious local applications to access sensitive user data by exploiting the weakened code-signing enforcement before the patch in macOS 15.6.

For European organizations, this vulnerability poses a risk primarily to confidentiality of sensitive user data on macOS devices. Organizations with employees or systems running vulnerable versions of macOS could see unauthorized access to protected data if a malicious app is introduced locally, for example through social engineering or insider threats. This could lead to exposure of personal data, intellectual property, or other sensitive information, potentially violating GDPR and other data protection regulations. Although the attack requires local access and user interaction, the widespread use of macOS in certain sectors (creative industries, software development, finance) in Europe means that the impact could be significant if exploited. The lack of known exploits in the wild reduces immediate risk, but the medium severity and confidentiality impact warrant prompt patching. Additionally, organizations relying on macOS for critical workflows should be aware that this vulnerability could be leveraged in targeted attacks or insider threat scenarios to bypass data protections.

1. Immediate deployment of macOS Sequoia 15.6 or later on all vulnerable systems to ensure the patch addressing this downgrade issue is applied. 2. Implement strict application whitelisting and endpoint protection to prevent unauthorized or untrusted applications from executing, reducing the risk of malicious apps exploiting this vulnerability. 3. Educate users about the risks of installing or running untrusted applications and the importance of verifying app sources to minimize user interaction risks. 4. Monitor local system logs and application behavior for signs of suspicious activity or attempts to bypass code-signing restrictions. 5. Use Mobile Device Management (MDM) solutions to enforce security policies and automate patch management for macOS devices. 6. Review and tighten internal policies around software installation privileges to limit local attack vectors. 7. Conduct regular security audits and vulnerability assessments on macOS endpoints to ensure compliance and detect potential exploitation attempts early.