CVE-2021-30832
📋 TL;DR
CVE-2021-30832 is a memory corruption vulnerability in macOS that allows local attackers to escalate privileges. This affects macOS Catalina and Big Sur systems. Attackers could gain root access on unpatched systems.
💻 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
Local attacker gains full root privileges, compromising the entire system and potentially accessing all data and resources.
Likely Case
Malicious local user or malware elevates privileges to install persistent backdoors, access sensitive files, or bypass security controls.
If Mitigated
With proper patching and least privilege principles, impact is limited to denial of service at most.
🎯 Exploit Status
Exploit requires local access and some technical knowledge. Multiple security advisories confirm weaponization.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Security Update 2021-005 Catalina, macOS Big Sur 11.6
Vendor Advisory: https://support.apple.com/en-us/HT212804
Restart Required: Yes
Instructions:
1. Open System Preferences > Software Update. 2. Install Security Update 2021-005 (Catalina) or update to macOS Big Sur 11.6. 3. Restart the system when prompted.
🔧 Temporary Workarounds
Restrict local user privileges
allLimit standard user accounts to prevent privilege escalation attempts
sudo dscl . -append /Groups/admin GroupMembership username
🧯 If You Can't Patch
- Implement strict least privilege principles for all user accounts
- Monitor for suspicious privilege escalation attempts and unauthorized root access
🔍 How to Verify
Check if Vulnerable:
Check macOS version: if running Catalina (10.15) or Big Sur (11.0-11.5.2), system is vulnerable.Check Version:
sw_versVerify Fix Applied:
Verify macOS version is Security Update 2021-005 Catalina or Big Sur 11.6 or later.📡 Detection & Monitoring
Log Indicators:
- Unexpected privilege escalation events in system logs
- Unauthorized root access attempts
Network Indicators:
- None - this is a local exploit
SIEM Query:
source="macos_system_logs" AND (event="privilege_escalation" OR user="root" AND action="unexpected_login")