CVE-2022-31810
📋 TL;DR
A stack-based buffer overflow vulnerability in SiPass integrated server applications allows unauthenticated remote attackers to crash the server by sending specially crafted configuration client login packets. This affects all SiPass integrated versions before V2.90.3.8, creating a denial of service condition.
💻 Affected Systems
- SiPass integrated
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete server crash leading to sustained denial of service, potentially disrupting physical access control systems.
Likely Case
Server crash requiring manual restart, causing temporary access control system downtime.
If Mitigated
No impact if patched or properly network-isolated.
🎯 Exploit Status
Buffer overflow in packet size checking suggests relatively straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V2.90.3.8 or later
Vendor Advisory: https://cert-portal.siemens.com/productcert/pdf/ssa-924149.pdf
Restart Required: Yes
Instructions:
1. Download V2.90.3.8 or later from Siemens support portal. 2. Backup current configuration. 3. Install update following vendor documentation. 4. Restart SiPass integrated services.
🔧 Temporary Workarounds
Network Segmentation
allRestrict access to SiPass integrated server to trusted management networks only.
Configure firewall rules to allow only specific IPs/subnets to access SiPass server ports
Disable Unnecessary Services
allDisable configuration client login service if not required.
Consult Siemens documentation for service disable procedures
🧯 If You Can't Patch
- Implement strict network access controls to limit exposure
- Monitor for crash/restart events and implement redundancy if possible
🔍 How to Verify
Check if Vulnerable:
Check SiPass integrated version in administration interface or configuration files.Check Version:
Check via SiPass administration interface or consult Siemens documentation for version query commands.Verify Fix Applied:
Confirm version is V2.90.3.8 or later after update.📡 Detection & Monitoring
Log Indicators:
- Unexpected server crashes
- Multiple failed login attempts from single source
- Abnormal packet size warnings
Network Indicators:
- Unusual traffic to SiPass configuration port (default 443/TCP)
- Multiple connection attempts with varying packet sizes
SIEM Query:
source="sipass" AND (event="crash" OR event="restart") OR (destination_port=443 AND packet_size>threshold)