CVE-2022-31808
📋 TL;DR
This vulnerability allows authenticated users on SiPass integrated access control systems to execute arbitrary commands with root privileges through improper input sanitization in the telnet interface. Attackers with valid credentials can escalate privileges to gain full system control. Affected systems include SiPass integrated AC5102 (ACC-G2) and SiPass integrated ACC-AP devices.
💻 Affected Systems
- SiPass integrated AC5102 (ACC-G2)
- SiPass integrated ACC-AP
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where attackers gain root access, install persistent backdoors, manipulate access control systems, and potentially pivot to other network segments.
Likely Case
Privilege escalation by authenticated attackers to gain administrative control over the access control system, potentially modifying user permissions, door schedules, or disabling security features.
If Mitigated
Limited impact if telnet access is disabled, network segmentation is implemented, and strong authentication controls prevent unauthorized access to the interface.
🎯 Exploit Status
Exploitation requires authenticated access to telnet interface. The vulnerability involves command injection which is typically straightforward to exploit once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V2.85.44 for AC5102, V2.85.43 for ACC-AP
Vendor Advisory: https://cert-portal.siemens.com/productcert/pdf/ssa-658793.pdf
Restart Required: Yes
Instructions:
1. Download firmware update from Siemens support portal. 2. Backup current configuration. 3. Apply firmware update following vendor instructions. 4. Restart device. 5. Verify successful update and restore configuration if needed.
🔧 Temporary Workarounds
Disable Telnet Service
linuxDisable telnet interface and use secure alternatives like SSH if available
systemctl stop telnet
systemctl disable telnet
Network Segmentation
linuxRestrict network access to telnet interface using firewall rules
iptables -A INPUT -p tcp --dport 23 -j DROP
🧯 If You Can't Patch
- Disable telnet service completely and use alternative management interfaces
- Implement strict network access controls to limit telnet access to trusted administrative hosts only
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or CLI. If version is below V2.85.44 for AC5102 or V2.85.43 for ACC-AP, device is vulnerable.Check Version:
telnet [device_ip] then login and check version via system info commandVerify Fix Applied:
Verify firmware version shows V2.85.44 or higher for AC5102, or V2.85.43 or higher for ACC-AP. Test telnet interface for command injection attempts.📡 Detection & Monitoring
Log Indicators:
- Unusual telnet login attempts
- Multiple failed authentication attempts followed by successful login
- Suspicious command execution in telnet logs
Network Indicators:
- Telnet connections from unexpected sources
- Unusual telnet traffic patterns
- Command injection patterns in telnet sessions
SIEM Query:
source="telnet.log" AND ("command injection" OR "privilege escalation" OR "root access")