CVE-2017-17411
📋 TL;DR
CVE-2017-17411 is a critical remote code execution vulnerability in Linksys WVBR0 routers that allows unauthenticated attackers to execute arbitrary commands with root privileges via the web management portal. The vulnerability stems from improper input validation in system calls, enabling complete device compromise. All users of affected Linksys WVBR0 routers are at risk.
💻 Affected Systems
- Linksys WVBR0
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover with root privileges, allowing attackers to install persistent malware, pivot to internal networks, intercept all network traffic, or brick the device.
Likely Case
Attackers install backdoors, cryptocurrency miners, or botnet clients, then use the compromised router to attack other devices on the network or launch external attacks.
If Mitigated
With proper network segmentation and access controls, impact is limited to the router itself, though it could still be used to attack other devices on the same network segment.
🎯 Exploit Status
Multiple public exploits exist including Metasploit modules. Exploitation requires only HTTP access to the management interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Linksys firmware updates for specific version
Vendor Advisory: https://www.linksys.com/us/support-article?articleNum=148385
Restart Required: Yes
Instructions:
1. Log into Linksys router web interface. 2. Navigate to Administration > Firmware Upgrade. 3. Check for and apply latest firmware. 4. Reboot router after update completes.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to the web management interface
Log into router web interface > Administration > Remote Management > Disable
Network Segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Replace affected router with supported model
- Implement strict firewall rules blocking all external access to router management ports (typically 80, 443, 8080)
🔍 How to Verify
Check if Vulnerable:
Check if Linksys WVBR0 is running unpatched firmware. Test with Metasploit module 'exploit/linux/http/linksys_wvbr0_cmd_injection' if authorized.Check Version:
Log into router web interface > Status > Router Information > Firmware VersionVerify Fix Applied:
Verify firmware version is updated to latest available from Linksys. Test exploitation attempts fail.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to web management interface with shell commands
- Failed login attempts followed by command injection patterns
- System logs showing unexpected process execution
Network Indicators:
- HTTP requests containing shell metacharacters (;, |, &, $) to router management port
- Outbound connections from router to suspicious IPs
SIEM Query:
source="router_logs" AND (uri="*;*" OR uri="*|*" OR uri="*`*" OR uri="*$(*")🔗 References
- http://www.securityfocus.com/bid/102212
- https://github.com/rapid7/metasploit-framework/pull/9336
- https://www.exploit-db.com/exploits/43363/
- https://www.exploit-db.com/exploits/43429/
- https://zerodayinitiative.com/advisories/ZDI-17-973
- http://www.securityfocus.com/bid/102212
- https://github.com/rapid7/metasploit-framework/pull/9336
- https://www.exploit-db.com/exploits/43363/
- https://www.exploit-db.com/exploits/43429/
- https://zerodayinitiative.com/advisories/ZDI-17-973
