📄 Description (English)
A security flaw has been discovered in Trendnet TEW-657BRM 1.00.1. The impacted element is the function update_pcdb of the file /setup.cgi. The manipulation of the argument mac_pc_dba results in stack-based buffer overflow. The attack can be launched remotely. The exploit has been released to the public and may be used for attacks. The vendor confirms, that "[t]he product in question (...) has been discontinued and end of life since June 23, 2011, that is more than 14 years ago. We no longer provide support for this product, so we are not able to confirm the vulnerabilities. We will make an announcement on our website's product support page and notify customers who registered their products with us." This vulnerability only affects products that are no longer supported by the maintainer.
🤖 AI Executive Summary
CVE-2026-5350 is a stack-based buffer overflow vulnerability in the discontinued Trendnet TEW-657BRM router (firmware 1.00.1) affecting the /setup.cgi update_pcdb function. With a CVSS score of 8.8 and publicly available exploits, this poses significant risk to organizations still operating legacy network infrastructure. No vendor patch is available as the product reached end-of-life in 2011, requiring immediate device replacement or network isolation.
📄 Description (Arabic)
🤖 AI Intelligence Analysis Analyzed: Apr 23, 2026 18:07
🇸🇦 Saudi Arabia Impact Assessment
Saudi organizations operating legacy Trendnet TEW-657BRM routers face critical risk, particularly in: (1) Government agencies and NCA-regulated entities using older network infrastructure; (2) Banking sector (SAMA-regulated) if these devices are present in branch networks or legacy systems; (3) Healthcare facilities with outdated networking equipment; (4) Small-to-medium enterprises and educational institutions commonly using budget networking equipment. The public exploit availability significantly increases attack probability. Organizations in critical infrastructure sectors (energy, telecommunications) must prioritize identification and remediation of this hardware.
🏢 Affected Saudi Sectors
Government and Public Administration
Banking and Financial Services (SAMA-regulated)
Healthcare and Medical Facilities
Education and Universities
Small and Medium Enterprises
Telecommunications
Energy and Utilities
🎯 MITRE ATT&CK Techniques
⚖️ Saudi Risk Score (AI)
7.8
/ 10.0
🔧 Remediation Steps (English)
IMMEDIATE ACTIONS:
1. Conduct urgent inventory scan across all network segments to identify any Trendnet TEW-657BRM devices still in operation
2. Isolate identified devices from production networks immediately or power them down
3. Replace with current, vendor-supported router models from reputable manufacturers
4. Review firewall logs for any suspicious access attempts to port 80/443 on identified devices
PATCHING GUIDANCE:
- No vendor patch available; device replacement is mandatory
- Do not attempt firmware updates from unofficial sources
- Verify all replacement devices have active vendor support and security update mechanisms
COMPENSATING CONTROLS (if immediate replacement impossible):
- Implement network segmentation: isolate affected devices on separate VLAN with restricted access
- Deploy WAF/IPS rules blocking access to /setup.cgi endpoints
- Restrict administrative access to device management interfaces via IP whitelisting
- Disable remote management capabilities; use only local console access if required
- Monitor for exploitation attempts using IDS signatures detecting buffer overflow patterns
DETECTION RULES:
- Alert on HTTP POST requests to /setup.cgi with mac_pc_dba parameter containing unusual character sequences
- Monitor for stack overflow indicators: abnormal process termination, memory access violations on router devices
- Track failed authentication attempts and CGI errors on legacy Trendnet devices
- Implement network-based detection for known exploit payloads targeting this vulnerability
🔧 خطوات المعالجة (العربية)
الإجراءات الفورية:
1. إجراء مسح فوري للمخزون عبر جميع أجزاء الشبكة لتحديد أي أجهزة Trendnet TEW-657BRM لا تزال قيد التشغيل
2. عزل الأجهزة المحددة عن شبكات الإنتاج فوراً أو إيقاف تشغيلها
3. استبدالها بنماذج موجهات حالية مدعومة من البائع من الشركات المصنعة ذات السمعة الطيبة
4. مراجعة سجلات جدار الحماية للتحقق من أي محاولات وصول مريبة إلى المنافذ 80/443 على الأجهزة المحددة
إرشادات التصحيح:
- لا يتوفر تصحيح من البائع؛ استبدال الجهاز إلزامي
- عدم محاولة تحديثات البرامج الثابتة من مصادر غير رسمية
- التحقق من أن جميع الأجهزة البديلة لديها دعم نشط من البائع وآليات تحديث الأمان
الضوابط البديلة (إذا كان الاستبدال الفوري غير ممكن):
- تنفيذ تقسيم الشبكة: عزل الأجهزة المتأثرة على VLAN منفصل مع وصول مقيد
- نشر قواعد WAF/IPS لحظر الوصول إلى نقاط نهاية /setup.cgi
- تقييد الوصول الإداري إلى واجهات إدارة الجهاز عبر القائمة البيضاء للعناوين
- تعطيل قدرات الإدارة البعيدة؛ استخدام وصول وحدة التحكم المحلية فقط إذا لزم الأمر
- مراقبة محاولات الاستغلال باستخدام توقيعات IDS التي تكتشف أنماط تجاوز سعة المخزن المؤقت
قواعد الكشف:
- تنبيه طلبات HTTP POST إلى /setup.cgi مع معامل mac_pc_dba يحتوي على تسلسلات أحرف غير عادية
- مراقبة مؤشرات تجاوز المكدس: إنهاء العملية غير الطبيعي، انتهاكات الوصول إلى الذاكرة على أجهزة التوجيه
- تتبع محاولات المصادقة الفاشلة وأخطاء CGI على أجهزة Trendnet القديمة
- تنفيذ الكشف القائم على الشبكة عن حمولات الاستغلال المعروفة التي تستهدف هذه الثغرة
📋 Regulatory Compliance Mapping
🟢 NCA ECC 2024
ECC 2024 A.8.1 - Asset Management: Inventory and management of network devices
ECC 2024 A.8.2 - Lifecycle Management: End-of-life device handling and replacement
ECC 2024 A.12.6 - Change Management: Secure replacement of unsupported equipment
ECC 2024 A.14.2 - Vulnerability Management: Identification and remediation of known vulnerabilities
🔵 SAMA CSF
Identify (ID) - Asset Management: Identification of legacy and unsupported devices
Protect (PR) - Access Control: Network segmentation and isolation of vulnerable devices
Detect (DE) - Anomalies and Events: Detection of exploitation attempts
Respond (RS) - Incident Response: Procedures for handling compromised legacy devices
🟡 ISO 27001:2022
A.5.19 - Management of information security incidents and improvements
A.8.1 - Inventory of assets
A.8.2 - Ownership of assets
A.8.3 - Acceptable use of assets
A.12.6.1 - Management of technical vulnerabilities
🟣 PCI DSS v4.0.1
Requirement 2.4 - Document and implement policies and procedures to manage vendor-supplied defaults
Requirement 6.2 - Ensure security patches are installed within defined timeframe
Requirement 11.2 - Run automated vulnerability scans and address findings
🔗 References & Sources 4
🔗
https://github.com/panda666-888/vuls/blob/main/trendnet/tew-657brm/update_pcdb.md
cna@vuldb.com
Exploit
Third Party Advisory
🔗
https://vuldb.com/submit/781567
cna@vuldb.com
Third Party Advisory
VDB Entry
🔗
https://vuldb.com/vuln/354703
cna@vuldb.com
Third Party Advisory
VDB Entry
🔗
https://vuldb.com/vuln/354703/cti
cna@vuldb.com
Permissions Required
VDB Entry
📦 Affected Products / CPE 1 entries
trendnet:tew-657brm_firmware:1.00.1