CVE-2023-27324
📋 TL;DR
This vulnerability allows local attackers to escalate privileges on affected Parallels Desktop installations by exploiting improper initialization of environment variables in the Updater service. Attackers must first execute low-privileged code on the host system to leverage this flaw, gaining root privileges and executing arbitrary code. It affects users of Parallels Desktop on macOS systems.
💻 Affected Systems
- Parallels Desktop
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
An attacker gains full root access to the macOS host, enabling complete system compromise, data theft, or persistent malware installation.
Likely Case
A local user or malware with initial access escalates to root to bypass security controls, install additional payloads, or access sensitive data.
If Mitigated
With proper patching and least-privilege principles, the risk is reduced to minimal, as exploitation requires prior low-privileged access and can be blocked by updates.
🎯 Exploit Status
Exploitation requires local access and ability to execute low-privileged code; no public proof-of-concept is known, but details are disclosed in advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific patched version; likely included in updates after the advisory date.
Vendor Advisory: https://kb.parallels.com/125013
Restart Required: Yes
Instructions:
1. Open Parallels Desktop. 2. Go to Help > Check for Updates. 3. Install the latest available update. 4. Restart the system if prompted to ensure changes take effect.
🔧 Temporary Workarounds
Disable or restrict Updater service
macOSTemporarily disable the Parallels Desktop Updater service to reduce attack surface, but this may impact functionality.
sudo launchctl unload /Library/LaunchDaemons/com.parallels.desktop.launchdaemon.plist
🧯 If You Can't Patch
- Apply strict access controls to limit local user privileges and monitor for suspicious activity.
- Isolate affected systems from critical networks and consider using virtualization or sandboxing to contain potential exploits.
🔍 How to Verify
Check if Vulnerable:
Check the Parallels Desktop version and compare with the patched version listed in the vendor advisory; if outdated, assume vulnerable.Check Version:
grep -i version /Applications/Parallels\ Desktop.app/Contents/Info.plistVerify Fix Applied:
After updating, verify the version matches or exceeds the patched version from the advisory and ensure no unusual processes are running.📡 Detection & Monitoring
Log Indicators:
- Unusual process executions from the Updater service, privilege escalation attempts in system logs (e.g., sudo or launchd anomalies).
Network Indicators:
- Minimal network indicators as this is local; monitor for outbound connections post-exploitation from unexpected root processes.
SIEM Query:
Example: 'process_name:"Updater" AND parent_process:"launchd" AND user:"root"' to detect suspicious Updater activity.