CVE-2017-6866 in XHQ Server
Summary
by MITRE
A vulnerability was discovered in Siemens XHQ server 4 and 5 (4 before V4.7.1.3 and 5 before V5.0.0.2) that could allow an authenticated low-privileged remote user to gain read access to data in the XHQ solution exceeding his configured permission level.
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Analysis
by VulDB Data Team • 12/15/2022
The vulnerability identified as CVE-2017-6866 represents a critical access control flaw within Siemens XHQ server versions 4 and 5, specifically affecting installations prior to patch levels V4.7.1.3 and V5.0.0.2 respectively. This weakness resides in the server's authorization mechanisms, where properly authenticated users can exploit a privilege escalation vulnerability to access data beyond their designated permission levels. The issue demonstrates a fundamental breakdown in the principle of least privilege enforcement that is critical for maintaining data confidentiality and integrity within enterprise systems. The vulnerability is particularly concerning because it requires only low-privileged authentication credentials to exploit, making it accessible to users who should not have access to sensitive information.
The technical implementation of this flaw stems from inadequate validation of user permissions during data access requests within the XHQ server architecture. When authenticated users make requests for specific data elements, the system fails to properly verify that the requesting user possesses the necessary authorization levels to access the requested information. This weakness allows attackers to manipulate access control checks through crafted requests that bypass normal permission boundaries. The vulnerability is classified under CWE-284 which specifically addresses improper access control issues, where the system does not properly enforce access restrictions, enabling unauthorized data access. The flaw essentially creates a path where legitimate users can escalate their privileges without proper authorization, undermining the security model of the entire XHQ solution.
The operational impact of this vulnerability extends beyond simple unauthorized data access, as it can enable comprehensive data exfiltration and information gathering activities. An attacker with low-privileged access could potentially map the entire data landscape of the XHQ server, identifying sensitive information that should remain restricted to higher-privileged users. This vulnerability particularly affects industrial control systems and enterprise environments where XHQ servers are deployed for managing critical infrastructure data. The compromised system could lead to operational disruption, regulatory compliance violations, and potential safety risks in industrial environments where such systems control critical processes. The attack surface is broadened by the fact that the vulnerability affects multiple server versions and can be exploited remotely, making it particularly dangerous for organizations with distributed deployments.
Organizations should implement immediate mitigations including applying the vendor-provided patches for XHQ server versions 4 and 5, specifically updating to V4.7.1.3 and V5.0.0.2 respectively. Network segmentation and monitoring should be enhanced to detect unauthorized access patterns and potential exploitation attempts. Access controls should be reviewed and strengthened to ensure that user permissions are properly enforced and that the principle of least privilege is maintained. Additionally, organizations should consider implementing additional security controls such as intrusion detection systems and continuous monitoring solutions that can identify anomalous access behaviors that may indicate exploitation of this vulnerability. The ATT&CK framework categorizes this type of vulnerability under privilege escalation techniques, specifically targeting the 'Abuse Elevation of Privilege' tactic where adversaries leverage system weaknesses to gain higher-level permissions than initially granted.