CVE-2024-40861 Overview
CVE-2024-40861 is a local privilege escalation vulnerability affecting Apple macOS. An application running on an affected system can exploit improper checks to gain root privileges. Apple addressed the issue in macOS Sequoia 15 through improved validation logic. The vulnerability is categorized under [CWE-269] Improper Privilege Management.
The flaw requires local access and user interaction, but successful exploitation grants complete control over the affected system. Attackers can leverage this vector as a post-compromise step following initial code execution through phishing, malicious installers, or supply chain attacks.
Critical Impact
A malicious application can escalate to root privileges, resulting in full compromise of confidentiality, integrity, and availability on affected macOS hosts.
Affected Products
- Apple macOS versions prior to macOS Sequoia 15
- Applications running under standard user contexts on affected macOS builds
- Systems where the vulnerable component ships as part of the base operating system
Discovery Timeline
- 2024-09-17 - CVE-2024-40861 published to NVD
- 2024-09-17 - Apple releases fix in macOS Sequoia 15
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-40861
Vulnerability Analysis
CVE-2024-40861 is a local privilege escalation vulnerability in macOS. Apple's advisory states the issue was addressed with improved checks, indicating that validation logic in a privileged system component failed to properly verify caller identity, input parameters, or state prior to performing a sensitive operation. The vulnerability maps to [CWE-269] Improper Privilege Management.
Exploitation requires an attacker to first execute code on the target system, typically through a malicious application. Once running, the application invokes the vulnerable code path to elevate its privileges to root. Apple has not publicly disclosed the specific component or subsystem containing the flaw.
The EPSS score is 0.211%, reflecting low observed exploitation probability at this time. However, local privilege escalation flaws in macOS are frequently chained with initial access vectors by advanced threat actors targeting endpoints.
Root Cause
Apple's description attributes the vulnerability to insufficient checks in a privileged operation. The fix introduced additional validation, consistent with improper privilege management patterns where a lower-privileged process can influence or bypass a privileged operation. Specific technical details have not been publicly released by Apple.
Attack Vector
An attacker must have local code execution on the target macOS host, typically through delivery of a malicious application. User interaction is required to run the malicious binary. Once executed, the application invokes the vulnerable code path to gain root privileges without further user consent.
The vulnerability mechanism relies on abusing improper validation in a privileged macOS component. See the Apple Support Article and Full Disclosure Security Post for additional technical context.
Detection Methods for CVE-2024-40861
Indicators of Compromise
- Unexpected processes running with root or uid=0 privileges spawned from user-writable directories such as /Users/, /tmp/, or ~/Downloads/
- Unsigned or ad-hoc signed binaries executing privileged system operations shortly after user launch
- Creation or modification of files under /Library/LaunchDaemons/ or /System/Library/ by non-administrative user sessions
Detection Strategies
- Monitor macOS Endpoint Security framework events for ES_EVENT_TYPE_NOTIFY_EXEC calls where a child process transitions to uid=0 without a legitimate sudo or authorization prompt
- Baseline expected privileged operations and alert on deviations, particularly for applications outside the Mac App Store or notarized developer distributions
- Track process ancestry to identify user-launched applications spawning root-level children via non-standard IPC channels
Monitoring Recommendations
- Enable Unified Logging with the com.apple.securityd and com.apple.authd subsystems to capture authorization decisions
- Forward macOS telemetry to a central SIEM for correlation across endpoints and time-series analysis of privilege transitions
- Track macOS version distribution across the fleet to identify hosts still running builds prior to macOS Sequoia 15
How to Mitigate CVE-2024-40861
Immediate Actions Required
- Upgrade all affected macOS endpoints to macOS Sequoia 15 or later as the primary remediation
- Inventory macOS devices in the environment and prioritize patching systems that run untrusted third-party applications
- Restrict installation of unsigned or non-notarized applications through Gatekeeper and MDM policy enforcement
Patch Information
Apple addressed CVE-2024-40861 in macOS Sequoia 15 with improved checks in the affected component. Refer to the Apple Support Article for the official fix advisory and download instructions.
Workarounds
- No official workaround exists; applying the macOS Sequoia 15 update is the only supported remediation
- Limit local user accounts to standard privileges and enforce application allowlisting via MDM until systems are patched
- Disable execution of downloaded binaries from untrusted sources using Gatekeeper policies and quarantine attribute enforcement
# Verify macOS version on affected hosts
sw_vers -productVersion
# Enforce Gatekeeper to allow only App Store and identified developers
sudo spctl --master-enable
# List quarantined binaries in user download directories
xattr -r -p com.apple.quarantine ~/Downloads/
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
