CVE-2023-26848
📋 TL;DR
This CVE describes a command injection vulnerability in TOTOlink A7100RU routers via the org parameter in the setting/delStaticDhcpRules endpoint, allowing attackers to execute arbitrary commands on the device. It affects users of this specific router model running the vulnerable firmware version, potentially leading to full system compromise.
💻 Affected Systems
- TOTOlink A7100RU
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete takeover of the router, enabling attackers to intercept traffic, deploy malware, or pivot to internal networks.
Likely Case
Remote code execution leading to device compromise, data theft, or denial of service.
If Mitigated
Limited impact if the router is isolated or patched, but still poses a risk if exposed.
🎯 Exploit Status
Exploitation requires authentication to the router's web interface; public proof-of-concept code is available in GitHub repositories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch is available; monitor the vendor's website for firmware updates and apply them immediately when released.
🔧 Temporary Workarounds
Disable Remote Management
allTurn off remote access to the router's web interface to prevent external exploitation.
Access router settings via web interface, navigate to Remote Management or similar, and disable it.
Restrict Network Access
allUse firewall rules to limit access to the router's management interface to trusted IPs only.
Configure firewall on router or upstream device to block inbound traffic to port 80/443 except from authorized networks.
🧯 If You Can't Patch
- Isolate the router on a separate VLAN to limit lateral movement in case of compromise.
- Implement strong authentication and monitor logs for suspicious activity related to the delStaticDhcpRules endpoint.
🔍 How to Verify
Check if Vulnerable:
Check the router's firmware version via the web interface under System or Admin settings; if it matches V7.4cu.2313_B20191024, it is vulnerable.Check Version:
Log into the router's web interface and navigate to the firmware or system info page; no direct CLI command is typically available.Verify Fix Applied:
After applying any update, verify the firmware version has changed to a newer, non-vulnerable release.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /setting/delStaticDhcpRules with suspicious org parameters containing shell commands.
Network Indicators:
- Anomalous outbound connections from the router to unknown IPs, indicating potential command execution.
SIEM Query:
source="router_logs" AND url="/setting/delStaticDhcpRules" AND org=*"|"* OR org=*"&"* OR org=*"`"*