📄 Description (English)
A buffer overflow vulnerability in the UPnP DeletePortMapping() command in Zyxel VMG4005-B50B firmware versions through 5.13(ABRL.5.4)C0 could allow an adjacent attacker to trigger a temporary denial-of-service (DoS) condition affecting the UPnP function of the affected device.
🤖 AI Executive Summary
A buffer overflow vulnerability in Zyxel VMG4005-B50B gateway devices affects the UPnP DeletePortMapping() command, allowing adjacent network attackers to cause denial-of-service conditions. With CVSS 6.5 and no available patch, this poses moderate risk to organizations using these devices as network gateways. The vulnerability requires network adjacency, limiting exposure but affecting critical network infrastructure.
📄 Description (Arabic)
🤖 AI Intelligence Analysis Analyzed: Jun 3, 2026 07:00
🇸🇦 Saudi Arabia Impact Assessment
Saudi telecommunications providers (STC, Mobily, Zain) and ISPs using Zyxel VMG4005-B50B devices as customer gateways face service disruption risks. Government agencies and critical infrastructure operators relying on these devices for network segmentation could experience temporary loss of UPnP-dependent services. Banking sector organizations using these gateways for branch connectivity may experience intermittent service interruptions. The impact is primarily availability-focused, affecting network management and port mapping functions critical for remote access and service delivery.
🏢 Affected Saudi Sectors
Telecommunications
Internet Service Providers
Government
Banking
Healthcare
Energy
🎯 MITRE ATT&CK Techniques
⚖️ Saudi Risk Score (AI)
5.8
/ 10.0
🔧 Remediation Steps (English)
Immediate Actions:
1. Inventory all Zyxel VMG4005-B50B devices across the organization and document firmware versions
2. Disable UPnP functionality on affected devices if not operationally required
3. Implement network segmentation to restrict UPnP traffic to trusted adjacent networks only
4. Monitor affected devices for unexpected reboots or UPnP service failures
Compensating Controls:
5. Deploy firewall rules to block UPnP DeletePortMapping requests from untrusted sources
6. Implement network access controls (NAC) to restrict device access to authorized users/devices
7. Enable device logging and forward logs to SIEM for anomaly detection
8. Establish network monitoring for UPnP protocol anomalies
Detection Rules:
9. Monitor for repeated UPnP DeletePortMapping() commands from single source
10. Alert on UPnP service restarts or device reboots during normal operations
11. Track failed UPnP operations and port mapping errors
12. Contact Zyxel for firmware update availability and apply immediately upon release
🔧 خطوات المعالجة (العربية)
الإجراءات الفورية:
1. حصر جميع أجهزة Zyxel VMG4005-B50B في المنظمة وتوثيق إصدارات البرامج الثابتة
2. تعطيل وظيفة UPnP على الأجهزة المتأثرة إذا لم تكن مطلوبة تشغيلياً
3. تنفيذ تقسيم الشبكة لتقييد حركة UPnP للشبكات المجاورة الموثوقة فقط
4. مراقبة الأجهزة المتأثرة لإعادة التشغيل غير المتوقعة أو فشل خدمة UPnP
الضوابط البديلة:
5. نشر قواعد جدار الحماية لحظر طلبات UPnP DeletePortMapping من مصادر غير موثوقة
6. تنفيذ ضوابط الوصول إلى الشبكة (NAC) لتقييد وصول الجهاز للمستخدمين/الأجهزة المصرح بها
7. تفعيل تسجيل الجهاز وإعادة توجيه السجلات إلى SIEM للكشف عن الشذوذ
8. مراقبة الشبكة لشذوذ بروتوكول UPnP
قواعد الكشف:
9. مراقبة أوامر UPnP DeletePortMapping() المتكررة من مصدر واحد
10. التنبيه عند إعادة تشغيل خدمة UPnP أو إعادة تشغيل الجهاز أثناء العمليات العادية
11. تتبع عمليات UPnP الفاشلة وأخطاء تعيين المنافذ
12. الاتصال بـ Zyxel للحصول على تحديث البرامج الثابتة وتطبيقه فوراً عند توفره
📋 Regulatory Compliance Mapping
🟢 NCA ECC 2024
ECC 2024 A.8.1 - Asset Management and Inventory
ECC 2024 A.8.2 - Configuration Management
ECC 2024 A.12.6 - Capacity and Performance Management
ECC 2024 A.13.1 - Network Security
🔵 SAMA CSF
ID.AM-1 - Physical devices and software assets are inventoried
PR.IP-1 - System development and acquisition processes
DE.CM-1 - The network is monitored to detect potential cybersecurity events
RS.MI-1 - Incidents are contained
🟡 ISO 27001:2022
A.5.19 - Management of information security incidents
A.8.1 - Inventory of assets
A.8.2 - Ownership of assets
A.12.6 - Management of technical vulnerabilities