CVE-2016-8228 in Service Bridge
Summary
by MITRE
In Lenovo Service Bridge before version 4, a user with local privileges on a system could execute code with administrative privileges.
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Analysis
by VulDB Data Team • 10/13/2019
The vulnerability identified as CVE-2016-8228 represents a critical privilege escalation flaw within Lenovo Service Bridge software versions prior to 4.0. This issue stems from inadequate access control mechanisms that allow local users to exploit a design flaw in the service bridge component. The vulnerability is classified under CWE-276, which specifically addresses improper privilege management, making it a significant concern for system security. The flaw exists in the way the service bridge handles user authentication and authorization, creating a pathway for malicious actors with local access to elevate their privileges to administrative levels.
The technical implementation of this vulnerability involves a weakness in the privilege separation model employed by Lenovo Service Bridge. When a local user executes commands against the service bridge, the system fails to properly validate the user context, allowing unauthorized privilege escalation. This occurs because the service bridge component does not adequately enforce the principle of least privilege, enabling a user with standard local access to manipulate system resources that should require administrative permissions. The vulnerability operates at the kernel or system service level, making it particularly dangerous as it bypasses typical user-level security controls. Attackers can leverage this flaw to execute arbitrary code with elevated privileges, potentially gaining complete control over the affected system.
The operational impact of CVE-2016-8228 extends beyond simple privilege escalation, as it provides attackers with the foundation for broader system compromise. Once administrative privileges are obtained, threat actors can modify system configurations, install malware, access sensitive data, and establish persistent backdoors. This vulnerability aligns with ATT&CK technique T1068, which covers privilege escalation through local exploitation, and T1543, covering persistence mechanisms that can be established after privilege elevation. The vulnerability affects systems where Lenovo Service Bridge is installed, particularly those running older versions that have not received the necessary security patches. Organizations with multiple Lenovo devices running vulnerable software versions face significant risk, as a single compromised local account could lead to widespread administrative access throughout the network.
Mitigation strategies for this vulnerability require immediate patching of Lenovo Service Bridge to version 4.0 or later, which addresses the privilege escalation flaw through enhanced access control mechanisms. System administrators should conduct comprehensive inventory checks to identify all affected systems and implement remediation procedures. The patch addresses the underlying CWE-276 issue by implementing proper privilege validation and enforcement within the service bridge component. Additional mitigations include disabling unnecessary service bridge components when not required, implementing strict user access controls, and monitoring for unauthorized privilege escalation attempts. Organizations should also consider implementing principle of least privilege policies, ensuring that local user accounts have only the minimum permissions necessary for their operational requirements. Network segmentation and monitoring solutions should be deployed to detect suspicious privilege escalation activities, as the vulnerability could be leveraged as an initial access vector for more sophisticated attacks.