CVE-2021-1148
📋 TL;DR
This vulnerability allows authenticated remote attackers to execute arbitrary commands with root privileges on affected Cisco Small Business routers. Attackers need valid administrator credentials to exploit improper input validation in the web management interface. Organizations using Cisco RV110W, RV130, RV130W, or RV215W routers are affected.
💻 Affected Systems
- Cisco RV110W
- Cisco RV130
- Cisco RV130W
- Cisco RV215W
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of router with root access, allowing attacker to intercept all traffic, modify configurations, install persistent backdoors, and pivot to internal networks.
Likely Case
Attacker with stolen or default credentials gains full control of router, enabling traffic monitoring, credential harvesting, and network disruption.
If Mitigated
Limited impact due to strong authentication controls, network segmentation, and restricted management interface access.
🎯 Exploit Status
Exploitation requires valid admin credentials but is straightforward once obtained. Multiple public proof-of-concepts exist.
🛠️ 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 updates. Consider workarounds or replacement.
🔧 Temporary Workarounds
Disable Web Management Interface
allDisable the vulnerable web interface and use alternative management methods
Access CLI via SSH/Telnet and disable web interface
Restrict Management Access
allLimit web interface access to specific trusted IP addresses only
Configure firewall rules to restrict access to management IP
🧯 If You Can't Patch
- Replace affected routers with supported models that receive security updates
- Implement network segmentation to isolate routers from critical assets
🔍 How to Verify
Check if Vulnerable:
Check router model and firmware version against affected products listCheck Version:
show version (via CLI) or check web interface System Information pageVerify Fix Applied:
No fix available to verify. Verify workarounds by testing web interface accessibility📡 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 interface from unexpected sources
- Unusual outbound connections from router
SIEM Query:
source="router_logs" AND (http_method="POST" AND uri="/cgi-bin/*" AND (user_agent CONTAINS "curl" OR user_agent CONTAINS "wget"))