CVE-2026-6138 — AI Deep Analysis Summary

🚨 **Essence**: OS Command Injection in TOTOLINK A7100RU. 📉 **Consequences**: Full device compromise. Attackers can execute arbitrary system commands, leading to total loss of confidentiality, integrity, and availability.

🛡️ **Root Cause**: CWE-78 (OS Command Injection). 🐛 **Flaw**: Improper handling of the `mac` parameter in the `setAccessDeviceCfg` function within `/cgi-bin/cstecgi.cgi`. User input is not sanitized before execution.

📦 **Product**: TOTOLINK A7100RU Wireless Router. 🏭 **Vendor**: Totolink (China). 📅 **Affected Version**: 7.4cu.2313_b20191024. ⚠️ **Component**: CGI Handler (`cstecgi.cgi`).

💻 **Privileges**: High. The vulnerability allows execution with system-level privileges. 📂 **Data**: Full access to sensitive data, network configuration, and potentially other devices on the local network.…

🔓 **Threshold**: Low. 🌐 **Access**: Network Accessible (AV:N). 🔑 **Auth**: None Required (PR:N). 👁️ **UI**: None Required (UI:N). 🎯 **Complexity**: Low (AC:L). Easy to exploit remotely.

📜 **Public Exp?**: Yes. References indicate available exploits and technical descriptions on GitHub and VDB. 🔍 **Tags**: 'exploit', 'technical-description'.…

🔍 **Self-Check**: Scan for the specific CGI endpoint `/cgi-bin/cstecgi.cgi`. 🧪 **Test**: Attempt to inject commands via the `mac` parameter in `setAccessDeviceCfg`.…

🩹 **Official Patch**: Data does not explicitly confirm a released patch. 📝 **Status**: Published 2026-04-13. 🔄 **Action**: Check vendor site (totolink.net) for firmware updates immediately.…

🚧 **Workaround**: Block external access to the router's management interface. 🛑 **Mitigation**: Disable remote management features. 🧱 **Network Segmentation**: Isolate the router from untrusted networks.…

🔥 **Urgency**: Critical. 🚨 **Priority**: Immediate Action Required. With CVSS High score and no auth required, this is a high-risk vulnerability. Patch or isolate immediately to prevent remote takeover.