CVE-2025-56752
📋 TL;DR
This critical authentication bypass vulnerability in Ruijie RG-ES series switches allows remote attackers to gain full administrative control without credentials by sending a specially crafted HTTP POST request to /user.cgi. Organizations using affected Ruijie switch models with vulnerable firmware are at risk of complete network compromise.
💻 Affected Systems
- Ruijie RG-ES series switches
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain full administrative control over network switches, enabling them to reconfigure network topology, intercept all traffic, deploy persistent backdoors, and potentially pivot to other network segments.
Likely Case
Attackers bypass authentication to modify switch configurations, create administrative accounts, enable unauthorized network access, and potentially disrupt network operations.
If Mitigated
With proper network segmentation and access controls, impact is limited to isolated network segments, though the compromised switch remains vulnerable to further exploitation.
🎯 Exploit Status
The exploit requires only a single HTTP POST request with crafted parameters. Public proof-of-concept code is available in the GitHub repository referenced in the CVE.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
1. Monitor Ruijie official channels for security advisories. 2. Apply firmware updates immediately when available. 3. Consider upgrading to newer switch models if patches are not forthcoming.
🔧 Temporary Workarounds
Disable Web Management Interface
allDisable the HTTP/HTTPS web management interface to prevent exploitation via the vulnerable endpoint
configure terminal
no ip http server
no ip http secure-server
end
write memory
Restrict Management Access
allLimit management interface access to specific trusted IP addresses using ACLs
configure terminal
access-list 10 permit 192.168.1.0 0.0.0.255
ip http access-class 10
ip http secure-server access-class 10
end
write memory
🧯 If You Can't Patch
- Isolate affected switches in dedicated VLANs with strict firewall rules preventing external access
- Implement network monitoring for suspicious HTTP POST requests to /user.cgi and unauthorized configuration changes
🔍 How to Verify
Check if Vulnerable:
Check firmware version via CLI: show version | include ESW_1.0(1)B1P39. Test by attempting to access /user.cgi with crafted POST request (use caution).Check Version:
show versionVerify Fix Applied:
Verify firmware has been updated to a version later than ESW_1.0(1)B1P39. Test that authentication is required for administrative functions.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /user.cgi from unauthorized sources
- Unexpected configuration changes
- New administrative user creation
Network Indicators:
- HTTP traffic to switch management IP on port 80/443 containing /user.cgi in URI
- Unusual configuration changes via SNMP or CLI
SIEM Query:
source_ip=* AND destination_port IN (80,443) AND http_uri="/user.cgi" AND http_method="POST"