CVE-2025-43275: Apple macOS Race Condition Vulnerability

CVE-2025-43275 Overview

CVE-2025-43275 is a critical race condition vulnerability affecting multiple versions of Apple macOS that allows a malicious application to escape its sandbox environment. The vulnerability exists due to insufficient validation during concurrent operations, enabling attackers to exploit timing windows and gain unauthorized access to system resources outside the sandbox boundary.

Race conditions of this nature (CWE-362) occur when the proper outcome of a process depends on the timing of events, and attackers can manipulate this timing to bypass security controls. In this case, a sandboxed application can leverage the race condition to break out of its restricted environment, potentially gaining access to sensitive user data, system resources, and other applications.

Critical Impact

Successful exploitation allows malicious applications to completely bypass macOS sandbox protections, enabling unauthorized access to system resources, sensitive user data, and potential full system compromise.

Affected Products

• macOS Sequoia versions prior to 15.6
• macOS Sonoma versions prior to 14.7.7
• macOS Ventura versions prior to 13.7.7

Discovery Timeline

• 2025-07-30 - CVE-2025-43275 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2025-43275

Vulnerability Analysis

This vulnerability exploits a race condition within macOS's sandbox enforcement mechanism. The sandbox is a critical security feature that restricts applications to a limited set of resources and system calls, preventing malicious or compromised apps from accessing sensitive data or performing unauthorized operations.

The flaw resides in how macOS validates resource access requests during concurrent operations. When multiple threads or processes interact with sandbox boundary checks simultaneously, a window of opportunity exists where validation can be bypassed. This Time-of-Check to Time-of-Use (TOCTOU) scenario allows an attacker to modify conditions between the security check and the actual resource access.

The vulnerability is particularly severe because sandbox escape is one of the most dangerous attack outcomes on macOS. Once an application breaks out of its sandbox, it can access other applications' data, read keychain credentials, install persistent malware, or pivot to further system compromise.

Root Cause

The root cause is a race condition (CWE-362) in the macOS kernel's sandbox validation logic. During concurrent resource access operations, there is insufficient synchronization or atomic validation, creating exploitable timing windows. Apple addressed this by implementing additional validation checks to eliminate the race condition.

The vulnerability specifically affects how the sandbox subsystem handles authorization decisions when multiple operations occur in rapid succession. Without proper locking or atomic operations, the security decision made at time-of-check may not reflect the actual state at time-of-use.

Attack Vector

The vulnerability can be exploited by a malicious application running within a sandbox on macOS. The attack vector is classified as network-accessible, requiring no user interaction or prior privileges to exploit once malicious code is executing on the target system.

An attacker could deliver the exploit through:

• A malicious application distributed through unofficial channels
• A compromised or trojanized legitimate application
• Browser-based attacks that download and execute malicious code
• Phishing campaigns targeting macOS users

The attack mechanism involves triggering concurrent operations designed to exploit the timing window in sandbox validation. By carefully orchestrating the sequence and timing of resource access requests, the attacker can cause the sandbox enforcement to fail, allowing access to protected resources.

Detection Methods for CVE-2025-43275

Indicators of Compromise

• Unusual process behavior where sandboxed applications access resources outside their permitted container
• Unexpected file access patterns showing applications reading or writing to protected system directories
• Anomalous system call sequences indicating attempts to manipulate timing of security checks
• Process spawning or thread creation patterns consistent with race condition exploitation

Detection Strategies

• Monitor sandbox violation logs in macOS Console for unusual patterns or high-frequency events
• Implement endpoint detection rules for applications attempting to access resources outside their sandbox profile
• Deploy behavioral analysis to identify processes exhibiting concurrent operation patterns typical of TOCTOU attacks
• Review application entitlements and compare actual resource access against permitted sandbox capabilities

Monitoring Recommendations

• Enable verbose sandbox logging via log stream --predicate 'subsystem == "com.apple.sandbox"'
• Monitor for applications spawning multiple threads that simultaneously interact with sensitive system resources
• Track file system events for sandboxed applications attempting to access protected directories like /Library, /System, or other users' home folders
• Implement SentinelOne's behavioral AI detection to identify anomalous application behavior indicative of sandbox escape attempts

How to Mitigate CVE-2025-43275

Immediate Actions Required

• Update all affected macOS systems to the latest patched versions immediately (Sequoia 15.6, Sonoma 14.7.7, or Ventura 13.7.7)
• Review installed applications and remove any untrusted or unnecessary software
• Enable automatic security updates to ensure timely deployment of future patches
• Restrict application installation to the Mac App Store and identified developers via Gatekeeper settings

Patch Information

Apple has released security updates addressing this vulnerability across three macOS versions:

• macOS Sequoia 15.6 - See Apple Support Document 124149 for details
• macOS Sonoma 14.7.7 - See Apple Support Document 124150 for details
• macOS Ventura 13.7.7 - See Apple Support Document 124151 for details

Additional technical disclosure information is available through the Full Disclosure mailing list.

Workarounds

• Limit execution of untrusted applications until patches can be applied
• Increase Gatekeeper restrictions to only allow applications from the Mac App Store
• Use application firewalls to restrict network access for potentially vulnerable applications
• Consider deploying additional endpoint protection with behavioral analysis capabilities to detect sandbox escape attempts

# Verify macOS version and apply updates
sw_vers
# Check for available updates
softwareupdate --list
# Install all available security updates
softwareupdate --install --all
# Verify Gatekeeper is enabled for additional protection
spctl --status