CVE-2023-2270
📋 TL;DR
This vulnerability allows local users on Windows systems to write arbitrary files via a relative path vulnerability in the Netskope client service, which runs with SYSTEM privileges. Exploitation leads to arbitrary code execution with SYSTEM privileges. Only users with local access to affected Windows machines running vulnerable Netskope client versions are affected.
💻 Affected Systems
- Netskope Client
📦 What is this software?
Netskope by Netskope
⚠️ Risk & Real-World Impact
Worst Case
Local attacker gains full SYSTEM privileges on the Windows machine, enabling complete system compromise, data theft, persistence establishment, and lateral movement capabilities.
Likely Case
Local user escalates privileges to SYSTEM level, gaining full control over the endpoint for malicious activities.
If Mitigated
With proper access controls and monitoring, impact is limited to isolated endpoint compromise with detection of privilege escalation attempts.
🎯 Exploit Status
Exploitation requires local user access and knowledge of the relative path vulnerability. No public exploit code has been disclosed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: R100 and later
Vendor Advisory: https://www.netskope.com/company/security-compliance-and-assurance/security-advisories-and-disclosures/netskope-security-advisory-nskpsa-2023-001
Restart Required: Yes
Instructions:
1. Download Netskope client version R100 or later from Netskope portal. 2. Install the updated client on all affected endpoints. 3. Restart the system to ensure the new service is running.
🔧 Temporary Workarounds
Restrict Local User Access
windowsLimit local user access to machines running Netskope client to trusted users only.
Network Segmentation
allSegment networks to limit lateral movement if exploitation occurs.
🧯 If You Can't Patch
- Implement strict least privilege access controls for local users
- Monitor for unusual process creation with SYSTEM privileges and file writes in privileged directories
🔍 How to Verify
Check if Vulnerable:
Check Netskope client version via Control Panel > Programs and Features or command: netskope --versionCheck Version:
netskope --versionVerify Fix Applied:
Verify Netskope client version is R100 or later using same methods as above📡 Detection & Monitoring
Log Indicators:
- Unusual file writes to system directories by Netskope service
- Process creation with SYSTEM privileges from non-standard locations
Network Indicators:
- Localhost connections to Netskope service port followed by suspicious file operations
SIEM Query:
EventID=4688 AND NewProcessName contains 'netskope' AND SubjectUserName='SYSTEM' AND ParentProcessName contains 'svchost'