CVE-2022-25751
📋 TL;DR
This vulnerability affects multiple Siemens SCALANCE industrial network switches. An unauthenticated remote attacker can send specially crafted HTTP requests that crash affected devices due to improper HTTP header validation, causing denial of service.
💻 Affected Systems
- SCALANCE X302-7 EEC series
- SCALANCE X304-2FE
- SCALANCE X306-1LD FE
- SCALANCE X307-2 EEC series
- SCALANCE X307-3 series
- SCALANCE X308-2 series
- SCALANCE X310 series
- SCALANCE X320 series
- SCALANCE X408-2
- SCALANCE XR324 series
- SIPLUS NET SCALANCE X308-2
📦 What is this software?
Scalance Xr324 4m Poe Ts Firmware by Siemens
⚠️ Risk & Real-World Impact
Worst Case
Complete device crash requiring physical reboot, disrupting industrial network operations and potentially causing production downtime.
Likely Case
Device becomes unresponsive, requiring manual reboot and causing temporary network disruption.
If Mitigated
Minimal impact if devices are behind firewalls with restricted HTTP access and network segmentation.
🎯 Exploit Status
The vulnerability requires sending malformed HTTP headers to the web interface, which is relatively simple to craft.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V4.1 or later
Vendor Advisory: https://cert-portal.siemens.com/productcert/pdf/ssa-836527.pdf
Restart Required: Yes
Instructions:
1. Download firmware V4.1 or later from Siemens Industrial Network Management. 2. Backup current configuration. 3. Upload new firmware via web interface or TFTP. 4. Reboot device. 5. Restore configuration if needed.
🔧 Temporary Workarounds
Disable HTTP/HTTPS web interface
allDisable the web management interface to prevent exploitation via HTTP requests.
Configure via CLI: no ip http server
Configure via CLI: no ip http secure-server
Restrict network access
allUse firewall rules to restrict access to the web interface (TCP ports 80/443) to trusted management networks only.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate SCALANCE devices from untrusted networks
- Deploy intrusion detection systems to monitor for malformed HTTP requests targeting these devices
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface or CLI. If version is below V4.1, device is vulnerable.Check Version:
CLI: show version | include SoftwareVerify Fix Applied:
Confirm firmware version is V4.1 or later and test with legitimate HTTP requests to ensure web interface functions properly.📡 Detection & Monitoring
Log Indicators:
- Device reboot logs
- Web interface access logs showing malformed HTTP requests
- System log entries indicating HTTP service crashes
Network Indicators:
- Sudden loss of connectivity to SCALANCE devices
- HTTP requests with malformed headers to switch IPs on ports 80/443
SIEM Query:
source="scalance_switches" AND (event_type="reboot" OR http_request contains "malformed")