CVE-2020-3323
📋 TL;DR
This vulnerability allows unauthenticated remote attackers to execute arbitrary code as root on affected Cisco Small Business routers via crafted HTTP requests to the web management interface. It affects users of Cisco RV110W, RV130, RV130W, and RV215W routers with the vulnerable firmware versions. Exploitation can lead to complete device compromise.
💻 Affected Systems
- Cisco RV110W
- Cisco RV130
- Cisco RV130W
- Cisco RV215W
📦 What is this software?
Rv110w Wireless N Vpn Firewall Firmware by Cisco
View all CVEs affecting Rv110w Wireless N Vpn Firewall Firmware →
⚠️ Risk & Real-World Impact
Worst Case
Full root-level compromise of the router, allowing attacker to intercept traffic, modify configurations, install persistent malware, or use the device as a pivot point into the internal network.
Likely Case
Remote code execution leading to device takeover, enabling attackers to steal credentials, disrupt network services, or launch further attacks from the compromised router.
If Mitigated
Limited impact if the web management interface is not exposed to untrusted networks and proper network segmentation is in place.
🎯 Exploit Status
Exploitation involves sending crafted HTTP requests, which is straightforward given public proof-of-concept code and the high CVSS score indicating low attack complexity.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Varies by model; refer to Cisco Security Advisory for specific fixed firmware versions (e.g., RV130W fixed in 1.0.3.55).
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-rv-rce-AQKREqp
Restart Required: Yes
Instructions:
1. Access the router's web management interface. 2. Navigate to the firmware update section. 3. Download the latest firmware from Cisco's support site for your specific model. 4. Upload and apply the firmware update. 5. Reboot the router as prompted.
🔧 Temporary Workarounds
Disable web management interface on WAN
allPrevent remote access to the vulnerable interface by disabling it on the WAN/Internet-facing side.
Access router web interface -> Firewall -> Basic Settings -> Disable 'Remote Management' or similar option.
Restrict access via firewall rules
allLimit access to the web management interface to trusted IP addresses only.
Access router web interface -> Firewall -> Access Rules -> Add rule to allow only specific source IPs to port 80/443.
🧯 If You Can't Patch
- Isolate affected routers in a dedicated network segment with strict firewall rules to limit exposure.
- Monitor network traffic for anomalous HTTP requests to the router's management interface and implement intrusion detection.
🔍 How to Verify
Check if Vulnerable:
Check the firmware version in the router's web interface under Administration -> Firmware Upgrade or similar, and compare with patched versions in the Cisco advisory.Check Version:
Log into router web interface and navigate to firmware info page; no direct CLI command universally available for all models.Verify Fix Applied:
Confirm the firmware version matches or exceeds the patched version listed in the Cisco advisory after update.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to management interface paths, especially with crafted parameters or unexpected payloads.
- Failed login attempts followed by successful exploitation attempts.
Network Indicators:
- HTTP traffic to router management ports (80, 443) from untrusted sources with abnormal request patterns.
- Outbound connections from the router to unknown IPs post-exploit.
SIEM Query:
source="router_logs" AND (url_path="/path_to_vulnerable_endpoint" OR http_method="POST" AND status_code=200 AND user_agent="malicious")