CVE-2025-31244: Apple macOS Auth Bypass Vulnerability

CVE-2025-31244 Overview

CVE-2025-31244 is a file quarantine bypass affecting Apple macOS. Apple addressed the flaw with additional validation checks in macOS Sequoia 15.5. A local application can leverage the weakness to break out of its sandbox and gain broader access to the host system.

The issue is categorized under [CWE-693] Protection Mechanism Failure, indicating that a security control intended to enforce isolation did not function as designed. Successful exploitation compromises confidentiality, integrity, and availability at the system scope.

Critical Impact
A sandboxed app can bypass macOS file quarantine and escape its sandbox, gaining access to resources outside its intended boundary.

Affected Products

Apple macOS versions prior to Sequoia 15.5
Applications relying on macOS sandbox and quarantine enforcement
Systems running third-party apps distributed outside the App Store

Discovery Timeline

2025-05-12 - CVE-2025-31244 published to the National Vulnerability Database
2025-05-12 - Apple releases macOS Sequoia 15.5 with the corrective patch
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-31244

Vulnerability Analysis

The vulnerability resides in the macOS file quarantine mechanism, which tags files originating from untrusted sources with the com.apple.quarantine extended attribute. Quarantine feeds into Gatekeeper and the App Sandbox to constrain what an untrusted process can execute or access.

When the quarantine check fails to evaluate every file operation path, a sandboxed application can introduce or manipulate files that should carry restrictions but do not. Bypassing this control allows the app to sidestep the sandbox profile applied to its process container.

The flaw represents a protection mechanism failure rather than a memory corruption bug. The sandbox itself continues to function, but a missing check permits access to a code path or resource that the sandbox intended to block.

Root Cause

Apple's advisory attributes the issue to insufficient validation in the quarantine enforcement logic. The fix adds checks that close the gap between quarantine attribute assignment and downstream sandbox decisions. See the Apple Security Advisory for the vendor description.

Attack Vector

Exploitation requires local, authenticated access with low privileges and no user interaction. An attacker must first execute code inside a sandboxed process, typically by convincing a user to run a malicious app or by chaining another vulnerability that yields code execution in a constrained context.

Once inside the sandbox, the attacker uses the quarantine bypass to reach files, IPC endpoints, or executables that the sandbox profile would otherwise restrict. Technical discussion is available on the Full Disclosure Mailing List Post.

Detection Methods for CVE-2025-31244

Indicators of Compromise

Sandboxed processes writing or executing files that lack the expected com.apple.quarantine extended attribute.
Child processes spawned by sandboxed applications that access resources outside the app container.
Unexpected modifications to files under ~/Library, /tmp, or shared group containers by App Store or notarized apps.

Detection Strategies

Monitor for xattr operations that strip or omit quarantine attributes on downloaded or app-created files.
Correlate execve and posix_spawn events from sandboxed parents against expected sandbox profiles.
Alert on macOS Endpoint Security events indicating sandbox violations or Gatekeeper assessment failures.

Monitoring Recommendations

Ingest Apple Endpoint Security Framework telemetry into a centralized analytics pipeline for behavioral review.
Track macOS build versions across the fleet and flag hosts running versions earlier than Sequoia 15.5.
Baseline normal file access patterns for sandboxed apps and alert on deviations touching sensitive directories.

How to Mitigate CVE-2025-31244

Immediate Actions Required

Update all macOS Sequoia endpoints to version 15.5 or later using Software Update or MDM enforcement.
Inventory installed third-party applications and remove any that are unsigned or unnecessary.
Restrict user ability to run apps downloaded from outside the App Store or trusted developer sources.

Patch Information

Apple resolved CVE-2025-31244 in macOS Sequoia 15.5 by introducing additional checks in the file quarantine enforcement path. The Apple Security Advisory lists this CVE among the addressed issues. Apply the update through system preferences, MDM policy, or softwareupdate on the command line.

Workarounds

No official workaround exists; upgrading to macOS Sequoia 15.5 is the supported remediation.
Reduce exposure by enforcing Gatekeeper in its strictest configuration and requiring notarized applications.
Limit installation privileges to administrators and audit new application installations through MDM logs.

bash

# Verify macOS version and trigger update to Sequoia 15.5 or later
sw_vers -productVersion
sudo softwareupdate --install --all --restart

# Confirm quarantine attribute is present on a downloaded file
xattr -p com.apple.quarantine ~/Downloads/example.dmg