📄 Description (English)
Microsoft HTTP Protocol Stack Remote Code Execution Vulnerability — Microsoft HTTP Protocol Stack contains a vulnerability in http.sys that allows for remote code execution.
🤖 AI Executive Summary
CVE-2021-31166 is a critical remote code execution vulnerability in Microsoft's HTTP Protocol Stack (http.sys) affecting Windows systems with CVSS 9.0. This vulnerability allows unauthenticated remote attackers to execute arbitrary code with kernel privileges by sending specially crafted HTTP requests. With public exploits available, this poses an immediate threat to all Windows-based infrastructure in Saudi Arabia, particularly critical systems in banking, government, and energy sectors.
📄 Description (Arabic)
🤖 AI Intelligence Analysis Analyzed: Apr 20, 2026 17:34
🇸🇦 Saudi Arabia Impact Assessment
This vulnerability poses critical risk to Saudi Arabia's essential infrastructure. Banking sector (SAMA-regulated institutions, ATM networks) faces direct threat of compromise and financial data theft. Government agencies and NCA systems running Windows servers are at severe risk. Energy sector (ARAMCO, power utilities) critical control systems and SCADA networks using Windows-based HTTP services are vulnerable. Telecom operators (STC, Mobily, Zain) managing network infrastructure and billing systems are exposed. Healthcare institutions managing patient data through Windows-based systems face data breach risks. Any organization running IIS or Windows HTTP services without patches is immediately exploitable.
🏢 Affected Saudi Sectors
Banking and Financial Services
Government and Public Administration
Energy and Utilities
Telecommunications
Healthcare
Critical Infrastructure
Defense and Security
🎯 MITRE ATT&CK Techniques
⚖️ Saudi Risk Score (AI)
9.5
/ 10.0
🔧 Remediation Steps (English)
IMMEDIATE ACTIONS:
1. Identify all Windows systems running http.sys (Windows Server 2016, 2019, 2022, Windows 10, Windows 11) in your environment
2. Isolate or restrict network access to unpatched systems immediately
3. Implement network segmentation to limit HTTP traffic exposure
4. Enable Windows Defender/Microsoft Defender real-time protection
PATCHING GUIDANCE:
1. Apply Microsoft security update KB5003637 (June 2021) or later immediately
2. Prioritize patching for internet-facing systems and critical infrastructure
3. Test patches in non-production environment first
4. Schedule emergency patching windows for critical systems
5. Verify patch installation with: systeminfo | findstr /I "KB5003637"
COMPENSATING CONTROLS (if immediate patching impossible):
1. Disable HTTP.sys if not required; use alternative HTTP implementations
2. Implement WAF (Web Application Firewall) rules to filter malicious HTTP requests
3. Restrict HTTP/HTTPS access via firewall to trusted sources only
4. Monitor for exploitation attempts using IDS/IPS signatures
5. Implement rate limiting on HTTP requests
DETECTION RULES:
1. Monitor for abnormal http.sys process behavior and kernel-mode crashes
2. Alert on HTTP requests with unusual header sizes or malformed content
3. Track failed http.sys operations in Event Viewer (System log, Event ID 31)
4. Monitor for unexpected kernel-mode code execution from http.sys context
5. Implement YARA rules for known exploit payloads
🔧 خطوات المعالجة (العربية)
الإجراءات الفورية:
1. تحديد جميع أنظمة Windows التي تقوم بتشغيل http.sys (Windows Server 2016، 2019، 2022، Windows 10، Windows 11) في بيئتك
2. عزل أو تقييد الوصول الشبكي للأنظمة غير المصححة فوراً
3. تنفيذ تقسيم الشبكة لتحديد تعرض حركة HTTP
4. تفعيل Windows Defender/Microsoft Defender الحماية في الوقت الفعلي
إرشادات التصحيح:
1. تطبيق تحديث أمان Microsoft KB5003637 (يونيو 2021) أو أحدث فوراً
2. إعطاء الأولوية لتصحيح الأنظمة المتصلة بالإنترنت والبنية التحتية الحرجة
3. اختبار التصحيحات في بيئة غير الإنتاج أولاً
4. جدولة نوافذ تصحيح طارئة للأنظمة الحرجة
5. التحقق من تثبيت التصحيح باستخدام: systeminfo | findstr /I "KB5003637"
الضوابط البديلة (إذا كان التصحيح الفوري مستحيلاً):
1. تعطيل HTTP.sys إذا لم يكن مطلوباً؛ استخدام تطبيقات HTTP بديلة
2. تنفيذ قواعد WAF (جدار حماية تطبيقات الويب) لتصفية طلبات HTTP الضارة
3. تقييد الوصول HTTP/HTTPS عبر جدار الحماية للمصادر الموثوقة فقط
4. مراقبة محاولات الاستغلال باستخدام توقيعات IDS/IPS
5. تنفيذ تحديد معدل على طلبات HTTP
قواعد الكشف:
1. مراقبة سلوك عملية http.sys غير الطبيعي وأعطال kernel-mode
2. تنبيه على طلبات HTTP برؤوس غير عادية أو محتوى معيب
3. تتبع عمليات http.sys الفاشلة في Event Viewer (سجل النظام، معرّف الحدث 31)
4. مراقبة تنفيذ الأكواد في kernel-mode غير المتوقع من سياق http.sys
5. تنفيذ قواعد YARA لحمولات الاستغلال المعروفة
📋 Regulatory Compliance Mapping
🟢 NCA ECC 2024
A.12.6.1 - Management of technical vulnerabilities
A.14.2.1 - Secure development policy
A.12.2.1 - Monitoring and logging
A.12.3.1 - Segregation of networks
🔵 SAMA CSF
ID.RA-1 - Asset management and vulnerability identification
PR.IP-12 - Security patch management
DE.CM-1 - Detection and analysis of anomalies
RS.RP-1 - Response planning
🟡 ISO 27001:2022
A.12.3.1 - Segregation of networks
A.12.6.1 - Management of technical vulnerabilities
A.14.2.1 - Secure development policy
A.12.2.1 - Monitoring and logging
🟣 PCI DSS v4.0
6.2 - Security patches must be installed within defined timeframe
11.2 - Vulnerability scanning and remediation
10.2 - Logging and monitoring of access
🔗 References & Sources 0
No references.
📦 Affected Products / CPE 1 entries
Microsoft:HTTP Protocol Stack