CVE-2025-43371: Apple Xcode Privilege Escalation Flaw

CVE-2025-43371 Overview

CVE-2025-43371 is a sandbox escape vulnerability affecting Apple Xcode. The flaw allows an app to break out of its sandbox boundaries, gaining access to resources outside the protected execution environment. Apple addressed the issue in Xcode 26 with improved checks.

The vulnerability is categorized under [CWE-284] Improper Access Control. It requires local access and user interaction to exploit. Successful exploitation results in high impact to confidentiality and integrity, with scope change indicating that the vulnerable component can affect resources beyond its security authority.

Critical Impact
An application running on a system with vulnerable Xcode versions can escape the macOS sandbox, accessing files and system resources that should be inaccessible to sandboxed processes.

Affected Products

Apple Xcode (versions prior to 26)
macOS development environments using Xcode
Applications built or run through affected Xcode toolchains

Discovery Timeline

2025-09-15 - CVE-2025-43371 published to NVD
2025-09-15 - Apple releases Xcode 26 with security fix
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-43371

Vulnerability Analysis

The vulnerability resides in Xcode's access control implementation. Apple's advisory describes the fix as the addition of improved checks, indicating that the prior implementation lacked sufficient validation when enforcing sandbox boundaries.

The macOS sandbox restricts an application's access to system resources, files, and inter-process communication channels. When sandbox enforcement contains gaps, a malicious or compromised app can perform actions outside its intended security profile. The CVSS scope change reflects this property: the impact extends beyond the sandboxed component to affect the broader system.

The vulnerability requires user interaction, meaning the victim must perform an action such as opening a malicious project or running an attacker-supplied app within Xcode. No prior privileges are required, which broadens the population of potential attackers.

Root Cause

The root cause is improper access control [CWE-284] in Xcode's sandbox enforcement logic. Apple's release notes attribute the fix to improved checks, suggesting the original code path failed to validate a security-relevant condition before granting access to a protected operation or resource.

Attack Vector

The attack vector is local. An attacker delivers a crafted application or Xcode project to a developer's machine. When the user interacts with the artifact through Xcode, the app exploits the gap in sandbox enforcement to read sensitive files, write outside its container, or invoke restricted APIs. The scope change permits effects on resources owned by other security domains.

No public proof-of-concept code is currently available. The vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog, and there is no evidence of active exploitation.

Detection Methods for CVE-2025-43371

Indicators of Compromise

Sandboxed processes spawned by Xcode accessing files outside their container path
Unexpected entitlement usage or system calls originating from build or run targets
Xcode child processes writing to user directories such as ~/Library outside expected sandbox containers

Detection Strategies

Monitor process lineage where Xcode or xcodebuild parents a process that performs filesystem operations outside the sandbox container
Audit sandbox_check and Mandatory Access Control (MAC) denial log entries in system.log for anomalies
Track installations of Xcode versions prior to 26 across developer endpoints using software inventory tools

Monitoring Recommendations

Enable endpoint telemetry on macOS developer workstations to capture process execution, file access, and entitlement usage
Centralize macOS unified logs and alert on sandbox violation events from com.apple.sandbox
Inventory Xcode versions across the fleet and flag hosts running releases earlier than Xcode 26

How to Mitigate CVE-2025-43371

Immediate Actions Required

Upgrade all instances of Apple Xcode to version 26 or later on developer workstations and build infrastructure
Restrict execution of untrusted Xcode projects and third-party application bundles on developer endpoints
Review macOS sandbox profile telemetry for anomalous activity originating from Xcode child processes

Patch Information

Apple released Xcode 26 to address CVE-2025-43371. Detailed advisory information is available in the Apple Support Document. The vulnerability is also referenced in the Full Disclosure Mailing List.

Workarounds

Avoid opening untrusted Xcode projects or running unverified applications through Xcode until the upgrade is applied
Limit developer accounts to least-privilege configurations to reduce the impact of a successful sandbox escape
Use application allowlisting on developer endpoints to block untrusted binaries from launching under Xcode

bash

# Verify installed Xcode version
xcodebuild -version

# Expected output should show Xcode 26 or later
# Xcode 26.0
# Build version 17A...