CVE-2025-11156
📋 TL;DR
A local privilege escalation vulnerability in Netskope's Windows agent allows authenticated users with Administrator privileges to improperly load a driver as a generic kernel service, triggering a system crash (Blue Screen of Death) and causing Denial of Service. This affects Windows systems running vulnerable versions of Netskope's NS Client agent. The vulnerability requires local administrative access to exploit.
💻 Affected Systems
- Netskope NS Client (Windows agent)
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete system crash resulting in sustained downtime, potential data loss from unsaved work, and disruption of business operations on affected endpoints.
Likely Case
Targeted DoS attacks against specific Windows workstations or servers by malicious insiders or compromised admin accounts, causing temporary unavailability.
If Mitigated
Limited impact due to proper access controls and monitoring of administrative privileges, with quick recovery through system reboots.
🎯 Exploit Status
Exploitation requires local administrative privileges, which limits attack surface but makes it dangerous in environments with over-privileged users or compromised admin accounts.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Netskope advisory NSKPSA-2025-005 for specific patched versions
Vendor Advisory: https://www.netskope.com/company/security-compliance-and-assurance/security-advisories-and-disclosures/netskope-security-advisory-nskpsa-2025-005
Restart Required: Yes
Instructions:
1. Review Netskope advisory NSKPSA-2025-005. 2. Update Netskope Windows agent to patched version. 3. Restart affected systems to complete installation. 4. Verify agent version post-update.
🔧 Temporary Workarounds
Restrict Local Administrator Privileges
windowsImplement least privilege principles to limit the number of users with local Administrator access on Windows systems running Netskope agent.
Monitor Driver Loading Events
windowsEnable and monitor Windows Event Logs for driver loading events (Event ID 6 in System log) to detect potential exploitation attempts.
🧯 If You Can't Patch
- Implement strict access controls to limit local Administrator privileges to essential personnel only
- Monitor systems for unexpected crashes or Blue Screen events and investigate root causes promptly
🔍 How to Verify
Check if Vulnerable:
Check Netskope agent version on Windows systems and compare against patched versions listed in vendor advisory NSKPSA-2025-005.Check Version:
Check Netskope agent version through Windows Programs and Features or Netskope client interfaceVerify Fix Applied:
Confirm Netskope agent version is updated to patched version specified in vendor advisory and verify system stability.📡 Detection & Monitoring
Log Indicators:
- Windows System Event ID 41 (unexpected shutdown), Event ID 1001 (Blue Screen data), unexpected driver loading events
Network Indicators:
- Unusual patterns of system reboots or downtime from affected endpoints
SIEM Query:
EventID=41 OR EventID=1001 | where Computer contains "affected_hostname" | stats count by Computer, TimeGenerated