CVE-2024-44102: Siemens Telecontrol Server Basic RCE Flaw

CVE-2024-44102 Overview

A critical insecure deserialization vulnerability has been identified in Siemens TeleControl Server Basic V3.1 across multiple product variants. The affected system allows remote users to send maliciously crafted serialized objects, enabling unauthenticated attackers to exploit the vulnerability and execute arbitrary code with SYSTEM privileges on the target device. This vulnerability affects systems with redundancy configured.

Critical Impact

Unauthenticated remote attackers can achieve full system compromise by exploiting insecure deserialization, resulting in arbitrary code execution with SYSTEM privileges.

Affected Products

• PP TeleControl Server Basic 1000 to 5000 V3.1 (6NH9910-0AA31-0AE1) - All versions < V3.1.2.1 with redundancy configured
• PP TeleControl Server Basic 256 to 1000 V3.1 (6NH9910-0AA31-0AD1) - All versions < V3.1.2.1 with redundancy configured
• PP TeleControl Server Basic 32 to 64 V3.1 (6NH9910-0AA31-0AF1) - All versions < V3.1.2.1 with redundancy configured
• PP TeleControl Server Basic 64 to 256 V3.1 (6NH9910-0AA31-0AC1) - All versions < V3.1.2.1 with redundancy configured
• PP TeleControl Server Basic 8 to 32 V3.1 (6NH9910-0AA31-0AB1) - All versions < V3.1.2.1 with redundancy configured
• TeleControl Server Basic 1000 V3.1 (6NH9910-0AA31-0AD0) - All versions < V3.1.2.1 with redundancy configured
• TeleControl Server Basic 256 V3.1 (6NH9910-0AA31-0AC0) - All versions < V3.1.2.1 with redundancy configured
• TeleControl Server Basic 32 V3.1 (6NH9910-0AA31-0AF0) - All versions < V3.1.2.1 with redundancy configured
• TeleControl Server Basic 5000 V3.1 (6NH9910-0AA31-0AE0) - All versions < V3.1.2.1 with redundancy configured
• TeleControl Server Basic 64 V3.1 (6NH9910-0AA31-0AB0) - All versions < V3.1.2.1 with redundancy configured
• TeleControl Server Basic 8 V3.1 (6NH9910-0AA31-0AA0) - All versions < V3.1.2.1 with redundancy configured
• TeleControl Server Basic Serv Upgr (6NH9910-0AA31-0GA1) - All versions < V3.1.2.1 with redundancy configured
• TeleControl Server Basic Upgr V3.1 (6NH9910-0AA31-0GA0) - All versions < V3.1.2.1 with redundancy configured

Discovery Timeline

• 2024-11-12 - CVE-2024-44102 published to NVD
• 2024-11-13 - Last updated in NVD database

Technical Details for CVE-2024-44102

Vulnerability Analysis

This insecure deserialization vulnerability (CWE-502) exists in the TeleControl Server Basic redundancy communication mechanism. The vulnerability allows unauthenticated remote attackers to execute arbitrary code with the highest system privileges available on Windows systems.

The vulnerability is particularly severe because it requires no authentication and can be exploited remotely over the network with no user interaction required. Successful exploitation grants the attacker SYSTEM-level privileges, providing complete control over the affected device. This represents a worst-case scenario for industrial control system security.

Root Cause

The root cause is improper handling of serialized objects received from remote users. The affected software deserializes user-supplied content without adequate validation or sanitization, allowing attackers to craft malicious serialized objects that execute arbitrary code when processed. This is a classic insecure deserialization pattern where the application trusts and processes serialized data from untrusted sources without proper security controls.

Attack Vector

The attack is conducted over the network and targets systems with redundancy configured. An attacker crafts a malicious serialized object containing code execution payloads and sends it to the vulnerable TeleControl Server Basic instance. When the server processes this serialized object, it deserializes the malicious content, triggering arbitrary code execution.

The deserialization vulnerability allows attackers to instantiate arbitrary objects and execute code during the deserialization process. The malicious payload is processed with SYSTEM privileges, giving attackers complete control over the target system. No authentication is required, and no user interaction is necessary for successful exploitation.

Detection Methods for CVE-2024-44102

Indicators of Compromise

• Unexpected network connections to TeleControl Server Basic on redundancy communication ports from unknown or suspicious IP addresses
• Unusual process spawning from TeleControl Server Basic service processes, particularly command shells or PowerShell instances
• SYSTEM-level processes exhibiting abnormal behavior or making unexpected network connections
• Log entries indicating deserialization errors or exceptions in TeleControl Server Basic logs

Detection Strategies

• Monitor network traffic for unusual serialized object patterns targeting TeleControl Server Basic redundancy ports
• Implement application whitelisting to detect unauthorized code execution from TeleControl Server processes
• Deploy endpoint detection and response (EDR) solutions to identify suspicious process behavior associated with deserialization attacks
• Configure SIEM rules to correlate network connections with process creation events on TeleControl Server systems

Monitoring Recommendations

• Enable verbose logging on TeleControl Server Basic instances to capture deserialization events and errors
• Monitor for privilege escalation attempts and SYSTEM-level process anomalies on affected servers
• Implement network segmentation monitoring to detect lateral movement attempts from potentially compromised TeleControl servers
• Review system event logs for unexpected service crashes or restarts that may indicate exploitation attempts

How to Mitigate CVE-2024-44102

Immediate Actions Required

• Update all affected TeleControl Server Basic installations to version V3.1.2.1 or later immediately
• If immediate patching is not possible, disable redundancy functionality on affected systems as a temporary mitigation
• Isolate TeleControl Server Basic systems from untrusted networks using firewalls and network segmentation
• Review and restrict network access to redundancy communication ports to only trusted systems

Patch Information

Siemens has released version V3.1.2.1 to address this vulnerability. Administrators should apply this update to all affected TeleControl Server Basic product variants. The official security advisory is available from the Siemens Security Advisory.

Workarounds

• Disable the redundancy feature if it is not operationally required until patching can be completed
• Implement strict network segmentation to limit access to TeleControl Server Basic systems from untrusted networks
• Deploy network-level intrusion detection/prevention systems (IDS/IPS) to monitor and block potential exploitation attempts
• Restrict administrative access to TeleControl Server systems and enforce least-privilege principles

# Network segmentation example - restrict access to TeleControl Server
# Add firewall rules to allow only trusted redundancy partners
# Example using Windows Firewall (run as Administrator)
netsh advfirewall firewall add rule name="Block TeleControl Redundancy" dir=in action=block protocol=tcp localport=<redundancy_port>
netsh advfirewall firewall add rule name="Allow Trusted Redundancy Partner" dir=in action=allow protocol=tcp localport=<redundancy_port> remoteip=<trusted_partner_ip>