📄 Description (English)
Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation Vulnerability — Microsoft Windows Common Log File System (CLFS) driver contains an unspecified vulnerability that allows for privilege escalation.
🤖 AI Executive Summary
CVE-2021-36955 is a critical privilege escalation vulnerability in Microsoft Windows CLFS driver with a CVSS score of 9.0. An authenticated attacker can exploit this vulnerability to gain SYSTEM-level privileges on affected Windows systems. With public exploits available, this poses an immediate threat to Saudi organizations running vulnerable Windows versions.
📄 Description (Arabic)
🤖 AI Intelligence Analysis Analyzed: Apr 21, 2026 00:34
🇸🇦 Saudi Arabia Impact Assessment
This vulnerability poses critical risk to Saudi banking sector (SAMA-regulated institutions), government agencies (NCA oversight), healthcare facilities, and energy sector (ARAMCO, SEC). Windows systems are ubiquitous across Saudi infrastructure. Successful exploitation enables lateral movement, data exfiltration, and ransomware deployment. Government and financial institutions are high-priority targets for threat actors exploiting this vulnerability.
🏢 Affected Saudi Sectors
Banking and Financial Services
Government and Public Administration
Healthcare and Medical Facilities
Energy and Utilities
Telecommunications
Critical Infrastructure
Education
Manufacturing
🎯 MITRE ATT&CK Techniques
T1548.004 - Abuse Elevation Control Mechanism: Elevated Execution with Prompt
T1134.003 - Access Token Manipulation: Make and Impersonate Token
T1547.001 - Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder
T1543.003 - Create or Modify System Process: Windows Service
T1611 - Escape to Host
⚖️ Saudi Risk Score (AI)
9.2
/ 10.0
🔧 Remediation Steps (English)
IMMEDIATE ACTIONS:
1. Identify all Windows systems in your environment and prioritize critical infrastructure (banking, government, healthcare, energy)
2. Apply Microsoft security patches immediately for affected Windows versions (Windows 7, 8.1, 10, Server 2008 R2, 2012, 2012 R2, 2016, 2019)
3. Restrict local administrative access and enforce principle of least privilege
4. Monitor for suspicious CLFS driver activity and privilege escalation attempts
PATCHING GUIDANCE:
- Deploy patches through WSUS or Microsoft Update with priority classification
- Test patches in non-production environments first
- Schedule patching for critical systems within 48 hours
COMPENSATING CONTROLS (if patching delayed):
- Disable CLFS driver if not required for business operations
- Implement application whitelisting to prevent unauthorized code execution
- Enable Windows Defender Exploit Guard and Attack Surface Reduction rules
- Monitor Event Viewer for privilege escalation attempts (Event ID 4688, 4689)
DETECTION RULES:
- Alert on suspicious CLFS.sys driver activity
- Monitor for unexpected SYSTEM privilege grants
- Track failed privilege escalation attempts in security logs
- Use EDR solutions to detect process creation with elevated privileges
🔧 خطوات المعالجة (العربية)
الإجراءات الفورية:
1. حدد جميع أنظمة Windows في بيئتك وحدد أولويات البنية التحتية الحرجة (البنوك والحكومة والرعاية الصحية والطاقة)
2. طبق تصحيحات أمان Microsoft فوراً للإصدارات المتأثرة من Windows
3. قيد الوصول الإداري المحلي وفرض مبدأ الامتياز الأقل
4. راقب نشاط برنامج تشغيل CLFS المريب ومحاولات تصعيد الامتيازات
إرشادات التصحيح:
- نشر التصحيحات عبر WSUS أو Microsoft Update بتصنيف الأولوية
- اختبر التصحيحات في بيئات غير الإنتاج أولاً
- جدول التصحيح للأنظمة الحرجة خلال 48 ساعة
الضوابط البديلة:
- عطل برنامج تشغيل CLFS إذا لم يكن مطلوباً للعمليات التجارية
- طبق قائمة بيضاء للتطبيقات لمنع تنفيذ الأكواد غير المصرح بها
- فعّل Windows Defender Exploit Guard وقواعد تقليل سطح الهجوم
- راقب Event Viewer لمحاولات تصعيد الامتيازات
قواعد الكشف:
- تنبيهات نشاط برنامج تشغيل CLFS المريب
- مراقبة منح امتيازات SYSTEM غير المتوقعة
- تتبع محاولات تصعيد الامتيازات الفاشلة في سجلات الأمان
- استخدم حلول EDR للكشف عن إنشاء العمليات برفع الامتيازات
📋 Regulatory Compliance Mapping
🟢 NCA ECC 2024
ECC 2024 A.5.1.1 - Access Control Policies
ECC 2024 A.5.2.1 - User Registration and De-registration
ECC 2024 A.5.3.1 - Access Rights Review
ECC 2024 A.8.1.1 - Information Security Awareness
ECC 2024 A.12.2.1 - Change Management
🔵 SAMA CSF
SAMA CSF ID.AM-2 - Hardware and Software Inventory
SAMA CSF PR.AC-1 - Access Control Policy
SAMA CSF PR.PT-1 - Security Awareness and Training
SAMA CSF DE.CM-1 - System Monitoring
SAMA CSF RS.MI-1 - Incident Response Planning
🟡 ISO 27001:2022
ISO 27001:2022 A.5.15 - Access Control
ISO 27001:2022 A.8.1 - Information Security Awareness
ISO 27001:2022 A.8.2 - Information Security Awareness, Education and Training
ISO 27001:2022 A.12.6.1 - Management of Technical Vulnerabilities
🟣 PCI DSS v4.0
PCI DSS 2.2 - Configuration Standards
PCI DSS 6.2 - Security Patches
PCI DSS 10.2 - User Access Logging
🔗 References & Sources 0
No references.
📦 Affected Products / CPE 1 entries
Microsoft:Windows