CVE-2022-25429
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on Tenda AC9 routers via a buffer overflow in the saveparentcontrolinfo function. Attackers can exploit this by sending specially crafted requests containing malicious time parameters. This affects all users running the vulnerable firmware version.
💻 Affected Systems
- Tenda AC9
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, credential theft, and lateral movement to other devices on the network.
Likely Case
Remote code execution allowing attackers to modify router settings, redirect DNS, or use the device as part of a botnet.
If Mitigated
If properly segmented and firewalled, impact limited to the router itself without access to internal network resources.
🎯 Exploit Status
Public exploit code exists in GitHub repositories. Buffer overflow via time parameter is straightforward to exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Tenda website for latest firmware
Vendor Advisory: Not publicly documented by vendor
Restart Required: Yes
Instructions:
1. Visit Tenda support website. 2. Download latest firmware for AC9. 3. Log into router admin panel. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and install new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router web interface
Log into router admin > System Tools > Remote Management > Disable
Restrict management interface access
allLimit which IPs can access router admin panel
Log into router admin > Security > Access Control > Add allowed IPs only
🧯 If You Can't Patch
- Segment router on isolated network segment
- Implement network firewall rules to block access to router management interface from untrusted networks
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin panel under System StatusCheck Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
Verify firmware version is newer than v15.03.2.21📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/saveParentControlInfo
- Multiple failed login attempts followed by buffer overflow patterns
Network Indicators:
- HTTP requests with unusually long time parameters to router management interface
- Traffic patterns suggesting router compromise
SIEM Query:
source="router_logs" AND (uri="/goform/saveParentControlInfo" OR time_parameter_length>100)