CVE-2021-1146
📋 TL;DR
This CVE allows authenticated remote attackers with administrator credentials to execute arbitrary commands with root privileges on affected Cisco Small Business routers. The vulnerability exists in the web-based management interface due to improper input validation. Attackers can exploit it by sending crafted HTTP requests to gain full control of the device.
💻 Affected Systems
- Cisco Small Business RV110W
- Cisco Small Business RV130
- Cisco Small Business RV130W
- Cisco Small Business RV215W
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of router with root access, allowing attacker to intercept all network traffic, install persistent backdoors, pivot to internal networks, and disable security functions.
Likely Case
Attacker with stolen or compromised admin credentials gains full control of router to monitor traffic, redirect connections, or use as foothold for further attacks.
If Mitigated
Limited impact if strong credential management, network segmentation, and access controls prevent unauthorized access to management interface.
🎯 Exploit Status
Exploitation requires valid admin credentials but is straightforward once credentials are obtained. No public exploit code available but trivial for skilled attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: None available
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-rv-command-inject-LBdQ2KRN
Restart Required: No
Instructions:
No official patch available. Cisco has not released software updates. Consider workarounds or replacement.
🔧 Temporary Workarounds
Disable Web Management Interface
allDisable the web-based management interface and use CLI or other management methods if available.
Restrict Management Access
allConfigure firewall rules to restrict access to management interface only from trusted IP addresses.
🧯 If You Can't Patch
- Replace affected devices with supported models that receive security updates
- Implement network segmentation to isolate affected routers from critical assets
🔍 How to Verify
Check if Vulnerable:
Check if device model is RV110W, RV130, RV130W, or RV215W. All versions are vulnerable.Check Version:
Login to web interface and check System Summary or use CLI command 'show version'Verify Fix Applied:
No fix available to verify. Verify workarounds by confirming web interface is disabled or access is restricted.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to management interface
- Multiple failed login attempts followed by successful login
- Commands executed via web interface with unusual parameters
Network Indicators:
- HTTP traffic to router management port from unexpected sources
- Unusual outbound connections from router
SIEM Query:
source="router_logs" AND (http_method="POST" AND uri="/cgi-bin/*" AND (user_agent="curl" OR user_agent="wget" OR user_agent="python"))