CVE-2013-3307
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary operating system commands on affected Linksys routers by injecting shell metacharacters in the ping_ip parameter of the apply.cgi script. Attackers can gain full control of the router, potentially compromising the entire network. Affected devices include Linksys E1000, E1200, and E3200 routers with vulnerable firmware versions.
💻 Affected Systems
- Linksys E1000
- Linksys E1200
- Linksys E3200
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise leading to network takeover, credential theft, malware deployment, and persistent backdoor installation.
Likely Case
Router configuration modification, network traffic interception, DNS hijacking, and credential harvesting from connected devices.
If Mitigated
Limited impact if routers are behind firewalls with strict inbound filtering on port 52000.
🎯 Exploit Status
Exploit requires network access to port 52000. No authentication needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: E1000: >2.1.02, E1200: >=2.0.05, E3200: >1.0.04
Vendor Advisory: https://web.archive.org/web/20140421001918/https://www.trustwave.com/spiderlabs/advisories/TWSL2013-008.txt
Restart Required: Yes
Instructions:
1. Download latest firmware from Linksys support site. 2. Log into router web interface. 3. Navigate to Administration > Firmware Upgrade. 4. Upload firmware file. 5. Wait for automatic reboot.
🔧 Temporary Workarounds
Block Port 52000
linuxPrevent external access to vulnerable service
iptables -A INPUT -p tcp --dport 52000 -j DROP
Disable Remote Management
allTurn off web interface access from WAN
🧯 If You Can't Patch
- Replace affected routers with supported models
- Segment network to isolate vulnerable routers
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under Administration > Firmware UpgradeCheck Version:
curl -s http://router-ip:52000/apply.cgi | grep -i versionVerify Fix Applied:
Confirm firmware version is above vulnerable ranges📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /apply.cgi with ping_ip parameter containing special characters
- Multiple failed login attempts followed by apply.cgi access
Network Indicators:
- TCP connections to port 52000 from external IPs
- HTTP POST requests to /apply.cgi with shell metacharacters in parameters
SIEM Query:
source_port=52000 AND (http_uri="/apply.cgi" AND http_method="POST" AND http_param="ping_ip" AND http_param_value MATCHES "[;&|`$()]+")