CVE-2019-8837
📋 TL;DR
This macOS vulnerability allows malicious applications to bypass file access restrictions and read protected files. It affects macOS High Sierra, Mojave, and Catalina before specific security updates. Users who haven't applied Apple's security updates are vulnerable.
💻 Affected Systems
- macOS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Malicious application gains unauthorized access to sensitive system files, user data, or credentials stored in protected locations.
Likely Case
Malware or compromised applications access restricted directories containing user documents, application data, or system configuration files.
If Mitigated
With proper application sandboxing and user permission controls, impact is limited to files accessible by user permissions.
🎯 Exploit Status
Requires user to execute malicious application; Apple has not disclosed technical details of the logic issue.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Catalina 10.15.2, Security Update 2019-002 Mojave, Security Update 2019-007 High Sierra
Vendor Advisory: https://support.apple.com/en-us/HT210788
Restart Required: Yes
Instructions:
1. Open System Preferences > Software Update. 2. Install available security updates. 3. Restart computer when prompted.
🔧 Temporary Workarounds
Application Sandbox Enforcement
allEnsure all applications run with appropriate sandbox restrictions
User Education
allTrain users to only install applications from trusted sources like Mac App Store
🧯 If You Can't Patch
- Restrict user installation of applications to App Store only via MDM or configuration profiles
- Implement application allowlisting to prevent execution of unauthorized applications
🔍 How to Verify
Check if Vulnerable:
Check macOS version: if running High Sierra, Mojave, or Catalina without the specified security updates, system is vulnerable.Check Version:
sw_versVerify Fix Applied:
Verify macOS version shows Catalina 10.15.2+, or that security updates 2019-002 (Mojave) or 2019-007 (High Sierra) are installed.📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns by applications, particularly to protected directories
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
source="macos" event_type="file_access" file_path="/protected/path/*" app_not_in_allowlist