CVE-2023-35055
📋 TL;DR
A buffer overflow vulnerability in the Yifan YF325 router's HTTP server allows remote attackers to execute arbitrary commands by sending specially crafted network requests. This affects YF325 routers running vulnerable firmware versions, potentially giving attackers full control over affected devices.
💻 Affected Systems
- Yifan YF325 router
📦 What is this software?
Yf325 Firmware by Yifanwireless
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, lateral movement to other devices, and botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify device configuration, steal credentials, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if device is behind firewall with strict inbound rules and network segmentation prevents lateral movement.
🎯 Exploit Status
The vulnerability is in the gozila_cgi function's next_page parameter handling, requiring only a crafted HTTP request. Public technical details available from Talos Intelligence.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No vendor advisory found at time of analysis
Restart Required: Yes
Instructions:
1. Check vendor website for firmware updates 2. Download latest firmware 3. Upload via web interface 4. Reboot device 5. Verify version update
🔧 Temporary Workarounds
Disable HTTP management interface
allDisable the vulnerable HTTP server if not required for management
Router-specific: Check web interface for HTTP disable option
Network access controls
linuxRestrict access to router management interface
iptables -A INPUT -p tcp --dport 80 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict firewall rules
- Implement network monitoring for exploit attempts and anomalous traffic
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface or via SSH: cat /proc/version or similar version commandCheck Version:
Router-specific: Check web interface or use telnet/SSH if availableVerify Fix Applied:
Verify firmware version is newer than v1.0_20221108 and test with known exploit payloads (in safe environment)📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to gozila_cgi with long next_page parameters
- Failed buffer overflow attempts in system logs
Network Indicators:
- HTTP requests with unusually long next_page parameter values
- Traffic to router management interface from unexpected sources
SIEM Query:
source="router_logs" AND (http_uri="*gozila_cgi*" AND http_param="*next_page=*" AND length(http_param)>100)