CVE-2023-27497: SAP Diagnostics Agent RCE Vulnerability

CVE-2023-27497 Overview

CVE-2023-27497 is a critical vulnerability in the EventLogServiceCollector component of SAP Diagnostics Agent version 720. Due to missing authentication and insufficient input sanitization, an attacker can execute malicious scripts on all connected Diagnostics Agents running on Windows systems. This vulnerability allows unauthenticated remote attackers to achieve complete system compromise without any user interaction.

Critical Impact

Successful exploitation enables attackers to completely compromise confidentiality, integrity, and availability of affected systems, potentially affecting all connected SAP Diagnostics Agents in an enterprise environment.

Affected Products

• SAP Diagnostics Agent version 720
• Microsoft Windows (all versions running the vulnerable agent)
• Connected Diagnostics Agent instances in SAP environments

Discovery Timeline

• April 11, 2023 - CVE-2023-27497 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2023-27497

Vulnerability Analysis

This vulnerability stems from a critical authentication bypass combined with missing input sanitization in the EventLogServiceCollector component of SAP Diagnostics Agent. The vulnerability is classified under CWE-306 (Missing Authentication for Critical Function), indicating that the affected component fails to properly verify that requests to execute operations originate from authenticated users.

The impact is particularly severe because the EventLogServiceCollector operates as a service with elevated privileges on Windows systems. When exploited, an attacker gains the ability to execute arbitrary scripts with the same privileges as the Diagnostics Agent service, which typically runs under a high-privilege account to perform system monitoring and diagnostics functions.

Root Cause

The root cause of CVE-2023-27497 is the absence of authentication mechanisms protecting the EventLogServiceCollector's script execution functionality. The component accepts and processes code without validating the source or sanitizing the input, creating a direct pathway for remote code execution. This design flaw allows any network-accessible attacker to submit malicious payloads that are executed without challenge.

Attack Vector

The attack vector is network-based and requires no privileges or user interaction. An attacker with network access to the SAP Diagnostics Agent can craft malicious requests targeting the EventLogServiceCollector service. The attack exploits the missing authentication by sending specially crafted payloads containing malicious scripts directly to the vulnerable endpoint. Since the component does not validate or sanitize input, these scripts are executed with the service's privileges on all connected Diagnostics Agents running on Windows, potentially enabling lateral movement across an entire SAP infrastructure.

The vulnerability mechanism involves crafting network requests that exploit the missing authentication in the EventLogServiceCollector service. Attackers can send unsanitized code payloads through the agent's network interface, which are then executed across all connected Windows-based Diagnostics Agent instances. For technical details on the vulnerability, refer to the SAP Knowledge Base Article.

Detection Methods for CVE-2023-27497

Indicators of Compromise

• Unusual script execution events originating from the SAP Diagnostics Agent service on Windows systems
• Unexpected network connections to the Diagnostics Agent service port from external or unauthorized sources
• Creation of new processes or child processes spawned by the EventLogServiceCollector component
• Modifications to system files or registry entries by the Diagnostics Agent service account

Detection Strategies

• Monitor Windows Event Logs for suspicious script execution events associated with the SAP Diagnostics Agent service
• Implement network traffic analysis to detect anomalous requests to the Diagnostics Agent's service ports
• Deploy endpoint detection rules to identify unauthorized code execution by the EventLogServiceCollector process
• Establish baseline behavior for SAP Diagnostics Agent communications and alert on deviations

Monitoring Recommendations

• Enable verbose logging on SAP Diagnostics Agent instances to capture all incoming requests
• Configure SIEM rules to correlate authentication failures with subsequent successful operations on Diagnostics Agents
• Implement network segmentation monitoring to detect unauthorized access attempts to SAP infrastructure
• Deploy SentinelOne agents on all systems running SAP Diagnostics Agent for real-time behavioral analysis and threat detection

How to Mitigate CVE-2023-27497

Immediate Actions Required

• Apply the security patch referenced in SAP Note 3305369 immediately to all affected SAP Diagnostics Agent installations
• Restrict network access to the Diagnostics Agent service to only authorized management systems
• Implement firewall rules to limit incoming connections to the EventLogServiceCollector component
• Audit all Windows systems running SAP Diagnostics Agent version 720 for signs of compromise

Patch Information

SAP has released a security patch addressing this vulnerability. Organizations should consult the SAP Knowledge Base Article for detailed patching instructions. Additional security guidance is available in the SAP Security Update Documentation. Ensure all SAP Diagnostics Agent version 720 installations are updated to the patched version as specified in the SAP security note.

Workarounds

• Isolate SAP Diagnostics Agent systems in a segmented network with strict access controls until patching is complete
• Disable the EventLogServiceCollector component if it is not required for operations
• Implement application-level firewalls or reverse proxies with authentication in front of the Diagnostics Agent
• Monitor and restrict outbound connections from systems running the vulnerable agent to limit potential data exfiltration

# Network isolation example - Windows Firewall rule to restrict Diagnostics Agent access
netsh advfirewall firewall add rule name="Block SAP Diagnostics Agent External" dir=in action=block protocol=tcp localport=<DIAGNOSTICS_AGENT_PORT> remoteip=any
netsh advfirewall firewall add rule name="Allow SAP Diagnostics Agent Trusted" dir=in action=allow protocol=tcp localport=<DIAGNOSTICS_AGENT_PORT> remoteip=<TRUSTED_MANAGEMENT_IP>