CVE-2025-24135: Apple macOS Privilege Escalation Flaw

CVE-2025-24135 Overview

CVE-2025-24135 is a privilege escalation vulnerability affecting Apple macOS. Apple addressed the issue with improved message validation in macOS Sequoia 15.3. An application running on a vulnerable system may be able to gain elevated privileges by leveraging insufficient validation of inter-process messages.

The weakness is tracked under CWE-276: Incorrect Default Permissions. Exploitation requires local access and user interaction, but a successful attack yields high impact on confidentiality, integrity, and availability. Apple documented the fix in the Apple Support Article 122068.

Critical Impact
A local application can escalate privileges on macOS versions prior to Sequoia 15.3, giving attackers the ability to execute code with elevated rights and access protected system resources.

Affected Products

Apple macOS versions prior to macOS Sequoia 15.3
Systems running vulnerable macOS builds without the January 2025 security update
Endpoints where third-party applications can invoke the affected inter-process messaging path

Discovery Timeline

2025-01-27 - CVE-2025-24135 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-24135

Vulnerability Analysis

CVE-2025-24135 stems from improper validation of messages processed by a macOS component. An application running with standard user privileges can craft messages that the receiving service handles without adequate checks. This allows the application to influence a higher-privileged process and gain elevated capabilities on the host.

Apple's advisory describes the fix as "improved message validation," indicating the pre-patch code path accepted or acted on messages that should have been rejected. The classification under CWE-276 suggests the vulnerable component operated with default permissions that were broader than necessary for the messages it processed.

Root Cause

The root cause is missing or insufficient validation of inbound messages between processes. When the vulnerable service received a malformed or unexpected message, it performed privileged operations on behalf of the caller. Combined with incorrect default permissions, this allowed a low-privileged app to trigger actions reserved for higher-privileged contexts.

Attack Vector

Exploitation is local. An attacker must first execute code on the target Mac, typically by convincing a user to run a malicious application or by chaining this issue with a separate initial-access flaw. User interaction is required, consistent with a scenario in which the victim launches the malicious app.

Once running, the app sends crafted messages to the vulnerable service and elevates to a higher privilege level. Additional technical context is available in the Full Disclosure mailing list post.

Detection Methods for CVE-2025-24135

Indicators of Compromise

Unsigned or ad-hoc signed applications spawning child processes with elevated entitlements shortly after launch
Unexpected modifications to files or directories that require administrator or root permissions
New LaunchDaemons, LaunchAgents, or privileged helper tools installed by user-space applications

Detection Strategies

Monitor for macOS endpoints running builds earlier than Sequoia 15.3 and correlate with process-launch telemetry
Alert on child processes that acquire higher privilege levels than their parent process
Baseline legitimate inter-process communication patterns and flag anomalous message flows targeting system services

Monitoring Recommendations

Ingest Endpoint Security Framework (ESF) events into a centralized analytics platform for privilege-transition analysis
Track installation of new privileged helper tools under /Library/PrivilegedHelperTools/
Review Unified Log entries for authorization prompts and XPC service errors preceding privilege changes

How to Mitigate CVE-2025-24135

Immediate Actions Required

Update all Apple macOS systems to macOS Sequoia 15.3 or later
Inventory endpoints still running unsupported or unpatched macOS builds and prioritize them for remediation
Restrict installation of untrusted applications through Gatekeeper policies and mobile device management (MDM) controls

Patch Information

Apple fixed CVE-2025-24135 in macOS Sequoia 15.3. Administrators should apply the update through Software Update or MDM-managed deployment. Full details are published in the Apple Support Article 122068.

Workarounds

Limit user accounts to standard (non-administrator) privileges to raise the cost of chained exploitation
Enforce application allow-listing so that only vetted binaries can execute on managed Macs
Require notarized and Developer ID-signed applications through Gatekeeper to reduce exposure to malicious installers

bash

# Verify the installed macOS version meets or exceeds the patched build
sw_vers -productVersion

# Trigger a software update check on a managed Mac
sudo softwareupdate -l
sudo softwareupdate -ia --restart