CVE-2025-55613
📋 TL;DR
A buffer overflow vulnerability in Tenda O3V2 routers allows attackers to execute arbitrary code by sending specially crafted requests to the fromSafeSetMacFilter function. This affects all users running vulnerable firmware versions. Successful exploitation could lead to complete device compromise.
💻 Affected Systems
- Tenda O3V2
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full router compromise, credential theft, network pivoting, and persistent backdoor installation.
Likely Case
Router crash/reboot causing service disruption, or limited code execution allowing network reconnaissance and traffic interception.
If Mitigated
Denial of service only if exploit attempts are blocked by network controls, though the vulnerability remains present.
🎯 Exploit Status
Public proof-of-concept exists in GitHub repository, making exploitation straightforward for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates. 2. Download latest firmware for O3V2. 3. Log into router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and install new firmware. 6. Reboot router after installation.
🔧 Temporary Workarounds
Disable remote administration
allPrevents external attackers from accessing vulnerable interface
Network segmentation
allIsolate router management interface from untrusted networks
🧯 If You Can't Patch
- Replace vulnerable router with different model/brand
- Implement strict network ACLs to limit access to router management interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is 1.0.0.12(3880) or earlier, assume vulnerable.Check Version:
Login to router admin interface and check System Status or Firmware Update sectionVerify Fix Applied:
Verify firmware version has been updated to a version later than 1.0.0.12(3880) or check vendor advisory for patched version.📡 Detection & Monitoring
Log Indicators:
- Multiple failed requests to router management interface
- Unusual POST requests containing long mac parameter values
- Router crash/reboot logs
Network Indicators:
- Unusual traffic patterns to router management port (typically 80/443)
- Requests with abnormally long parameter values
SIEM Query:
source="router_logs" AND (url="*fromSafeSetMacFilter*" OR parameter="*mac=*" AND length(parameter)>100)