macOS HM Surf Vuln Might Already Be Under Exploit by Major Malware Family
Summary: Microsoft indicated that while they have observed suspicious activity that could suggest attempts to exploit this vulnerability, they could not confirm whether the Adloader macOS malware family has directly used HM Surf. Adloader is known for its focus on persistent infection and data theft on macOS systems.
Microsoft has urged all macOS users to update their systems due to a vulnerability (CVE-2024-44133, CVSS 5.5) patched in the September macOS Sequoia updates. The flaw may be exploited by the Adloader macOS malware family. It targets Apple's Transparency, Consent, and Control (TCC) protections, potentially allowing unauthorized access to a device's camera, microphone, and location.
The vulnerability is limited to Safari, which has entitlements allowing it to bypass TCC protections. Microsoft’s Jonathan Bar Or demonstrated an exploit, called "HM Surf," by modifying Safari’s configuration files, using the Directory Service command line utility (dscl) to manipulate TCC protections. This method could allow attackers to access sensitive data without user knowledge.
Microsoft has implemented new detection strategies and observed suspicious activity linked to Adloader, though it couldn't confirm if the activity directly exploited HM Surf. Apple introduced new APIs to prevent such modifications, while other browsers like Firefox and Chromium are still working on similar protections.
Security Officer Comments:
The flaw centers around Safari’s entitlements within the TCC framework. Entitlements in macOS dictate what system resources an app can access. Safari, being a core Apple application, possesses more powerful entitlements compared to other apps. This elevated privilege allows Safari to bypass some of TCC's standard protections once access is granted by the user.
Suggested Corrections:
Apple addressed this vulnerability with the September macOS Sequoia updates, which included new APIs for App Group Containers. These APIs are intended to improve System Integrity Protection (SIP), a macOS feature that prevents unauthorized modifications to system files and configurations. By using these new APIs, macOS aims to restrict any app, including Safari, from altering its configuration files in a way that would disable TCC protections.
Link(s):
https://www.theregister.com/2024/10/21/microsoft_macos_hm_surf/