CVE-2025-43390
📋 TL;DR
A code-signing downgrade vulnerability in Intel-based Mac computers allows malicious apps to bypass security restrictions and access sensitive user data. This affects macOS systems before specific updates. Users with Intel-based Macs running vulnerable macOS versions are at risk.
💻 Affected Systems
- macOS
📦 What is this software?
Macos by Apple
macOS is Apple's desktop and laptop operating system powering Mac computers used by millions of professionals, developers, creative professionals, and enterprise users worldwide. Built on a Unix foundation with the Darwin kernel and modern Cocoa frameworks, macOS delivers a seamless ecosystem integr...
Learn more about Macos →⚠️ Risk & Real-World Impact
Worst Case
Malicious app gains unauthorized access to sensitive user data like passwords, financial information, or personal documents through bypassed security controls.
Likely Case
Malicious app accesses limited user data or system information by exploiting code-signing downgrade to run with elevated privileges.
If Mitigated
App sandboxing and other macOS security layers limit data exposure even if downgrade occurs.
🎯 Exploit Status
Requires user to install/run malicious app; exploitation depends on bypassing code-signing restrictions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Sequoia 15.7.2, macOS Tahoe 26.1
Vendor Advisory: https://support.apple.com/en-us/125634
Restart Required: Yes
Instructions:
1. Open System Settings 2. Click General 3. Click Software Update 4. Install available updates 5. Restart when prompted
🔧 Temporary Workarounds
Restrict App Installation Sources
allOnly allow apps from App Store and identified developers in System Settings
🧯 If You Can't Patch
- Use application allowlisting to restrict which apps can run
- Implement strict user privilege management and avoid admin accounts for daily use
🔍 How to Verify
Check if Vulnerable:
Check macOS version in System Settings > General > About and processor type in About This MacCheck Version:
sw_versVerify Fix Applied:
Verify macOS version is 15.7.2 or later for Sequoia, or 26.1 or later for Tahoe📡 Detection & Monitoring
Log Indicators:
- Unusual code-signing validation failures in system logs
- Unexpected app execution with elevated privileges
Network Indicators:
- Unusual outbound connections from newly installed apps
SIEM Query:
Process execution events where code-signing validation shows downgrade patterns