CVE-2025-11423
📋 TL;DR
This vulnerability in Tenda CH22 routers allows remote attackers to execute arbitrary code or cause denial of service through memory corruption. Attackers can exploit this without authentication by manipulating the page parameter in the SafeEmailFilter function. All users running the affected firmware version are at risk.
💻 Affected Systems
- Tenda CH22
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, and lateral movement to other devices on the network.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as part of a botnet.
If Mitigated
Denial of service causing router reboot or temporary unavailability if exploit attempts fail or are blocked.
🎯 Exploit Status
Public exploit code exists in GitHub repositories, making exploitation straightforward for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.tenda.com.cn/
Restart Required: Yes
Instructions:
1. Check Tenda's official website for firmware updates. 2. If available, download the latest firmware. 3. Log into router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply the new firmware. 6. Wait for router to reboot.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to the vulnerable web interface
Log into router admin → System Tools → Remote Management → Disable
Network Segmentation
allIsolate the router from critical internal networks
Use firewall rules to restrict router access to management VLAN only
🧯 If You Can't Patch
- Replace the vulnerable router with a different model that receives security updates
- Place the router behind a dedicated firewall with strict inbound filtering rules
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Status or Firmware Upgrade sectionCheck Version:
Log into router web interface and navigate to System Status pageVerify Fix Applied:
Verify firmware version has been updated to a version later than 1.0.0.1📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/SafeEmailFilter
- Multiple failed exploit attempts
- Router reboot logs without user action
Network Indicators:
- Unusual outbound connections from router
- Traffic patterns suggesting device compromise
- Exploit kit traffic targeting router IP
SIEM Query:
source="router_logs" AND (uri="/goform/SafeEmailFilter" OR message="memory corruption" OR message="exploit attempt")