CVE-2024-23816: Siemens Location Intelligence Auth Bypass

CVE-2024-23816 Overview

A critical authentication bypass vulnerability has been identified in Siemens Location Intelligence products. The vulnerability exists due to the use of a hard-coded secret value for computing a Keyed-Hash Message Authentication Code (HMAC). This cryptographic weakness allows an unauthenticated remote attacker to forge valid authentication tokens and gain full administrative access to the application without requiring any user interaction or prior credentials.

Critical Impact

Unauthenticated remote attackers can exploit this hardcoded credentials vulnerability to gain complete administrative control over affected Siemens Location Intelligence deployments, potentially compromising sensitive location data and system integrity.

Affected Products

• Location Intelligence Perpetual Large (9DE5110-8CA13-1AX0) - All versions < V4.3
• Location Intelligence Perpetual Medium (9DE5110-8CA12-1AX0) - All versions < V4.3
• Location Intelligence Perpetual Non-Prod (9DE5110-8CA10-1AX0) - All versions < V4.3
• Location Intelligence Perpetual Small (9DE5110-8CA11-1AX0) - All versions < V4.3
• Location Intelligence SUS Large (9DE5110-8CA13-1BX0) - All versions < V4.3
• Location Intelligence SUS Medium (9DE5110-8CA12-1BX0) - All versions < V4.3
• Location Intelligence SUS Non-Prod (9DE5110-8CA10-1BX0) - All versions < V4.3
• Location Intelligence SUS Small (9DE5110-8CA11-1BX0) - All versions < V4.3

Discovery Timeline

• 2024-02-13 - CVE-2024-23816 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2024-23816

Vulnerability Analysis

This vulnerability is classified under CWE-798 (Use of Hard-coded Credentials), representing a fundamental security design flaw in the affected Siemens Location Intelligence products. The application relies on a static, hard-coded secret value embedded within the software to compute HMAC signatures for authentication purposes. Since this secret value is identical across all installations of the affected versions, an attacker who discovers or extracts this value can forge authentication tokens indistinguishable from legitimate ones.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without requiring any prior authentication, user interaction, or special privileges. Successful exploitation grants complete administrative access, enabling attackers to view, modify, or delete location intelligence data, reconfigure the system, create additional administrative accounts, or use the compromised system as a pivot point for further network intrusion.

Root Cause

The root cause stems from a violation of secure development practices where developers embedded a cryptographic secret directly in the application code rather than implementing proper key management. This hard-coded secret is used to generate and validate HMAC tokens that control administrative access. Because the secret is static and shared across all deployments, any attacker who reverse-engineers the application binary or intercepts valid tokens can derive the secret and forge arbitrary authentication credentials.

Attack Vector

The attack can be executed remotely over the network without any authentication requirements. An attacker would need to either extract the hard-coded secret from the application binaries through reverse engineering or capture valid HMAC tokens through network interception to cryptographically derive the secret. Once the attacker possesses the hard-coded secret value, they can compute valid HMAC signatures for any administrative operation, effectively bypassing all authentication controls.

The vulnerability manifests in the HMAC computation function used for authentication validation. Because the secret key is hard-coded rather than dynamically generated or securely stored per-installation, attackers can forge valid authentication tokens. See the Siemens Security Advisory SSA-580228 for additional technical details.

Detection Methods for CVE-2024-23816

Indicators of Compromise

• Unexpected administrative logins or session creation from unrecognized IP addresses or at unusual times
• Multiple administrative actions performed by accounts that should not have such privileges
• Configuration changes to the Location Intelligence application without corresponding change requests
• Evidence of binary analysis tools or memory dumping utilities on systems with access to the application
• Network traffic patterns showing authentication attempts from external or suspicious sources

Detection Strategies

• Monitor authentication logs for administrative access patterns that deviate from established baselines
• Implement network intrusion detection rules to identify unusual traffic to Location Intelligence management interfaces
• Deploy file integrity monitoring on application binaries to detect potential reverse engineering attempts
• Review and correlate access logs for authentication events that occur without corresponding legitimate user activity

Monitoring Recommendations

• Enable verbose logging for all administrative authentication events within Location Intelligence
• Implement real-time alerting for administrative account creation or privilege modifications
• Monitor network segments hosting Location Intelligence for anomalous connection patterns
• Establish baseline metrics for administrative operations and alert on statistical deviations

How to Mitigate CVE-2024-23816

Immediate Actions Required

• Upgrade all affected Siemens Location Intelligence installations to version V4.3 or later immediately
• Restrict network access to the Location Intelligence management interface to trusted administrative networks only
• Audit all administrative accounts and remove any unauthorized or suspicious accounts
• Review recent administrative activity logs for signs of exploitation prior to patching

Patch Information

Siemens has released version V4.3 of Location Intelligence which addresses this vulnerability by implementing proper cryptographic key management instead of relying on hard-coded secrets. Organizations should obtain the update through their Siemens support channels. For detailed patch information and download instructions, refer to the Siemens Security Advisory SSA-580228.

Workarounds

• If immediate patching is not possible, isolate the Location Intelligence system behind a VPN or firewall with strict access controls
• Implement network segmentation to limit exposure of the application to only essential systems and users
• Deploy a web application firewall (WAF) to monitor and filter suspicious requests to the management interface
• Enable multi-factor authentication at the network perimeter level as an additional defense layer

# Example: Firewall rule to restrict administrative access
# Restrict Location Intelligence admin interface to trusted management network only
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP