CVE-2021-1179
📋 TL;DR
This vulnerability allows authenticated attackers to execute arbitrary code as root or cause denial of service on affected Cisco Small Business routers. Attackers need valid administrator credentials to exploit these input validation flaws in the web management interface. Organizations using 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 device compromise with root-level arbitrary code execution, allowing full control of the router and potential lateral movement into connected networks.
Likely Case
Device reboot causing temporary denial of service, disrupting network connectivity for connected users and services.
If Mitigated
Limited impact if strong authentication controls prevent unauthorized access to admin credentials.
🎯 Exploit Status
Exploitation requires valid administrator credentials but involves simple HTTP request crafting once credentials are obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: None available
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-rv-overflow-WUnUgv4U
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 vulnerable web-based management interface to prevent HTTP-based exploitation
Access router CLI via SSH/Telnet
Configure no ip http server
Configure no ip http secure-server
Restrict Management Access
allLimit management interface access to specific trusted IP addresses only
Configure access-list to permit only trusted management hosts
Apply access-list to vty lines and http interfaces
🧯 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 list. All versions of listed models are vulnerable.Check Version:
show versionVerify Fix Applied:
Verify web management interface is disabled or access is restricted to trusted IPs only.📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by successful login
- Unusual HTTP POST requests to management interface
- Device reboot logs without scheduled maintenance
Network Indicators:
- HTTP traffic to router management interface from unexpected sources
- Multiple authentication attempts from single source
SIEM Query:
source="router_logs" (event_type="authentication" AND result="success") OR (event_type="http_request" AND uri="/admin/*")