CVE-2016-8229 in Service Bridge
Summary
by MITRE
A cross-site request forgery vulnerability in Lenovo Service Bridge before version 4 could be exploited by an attacker with access to the DHCP server used by the system where LSB is installed.
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Analysis
by VulDB Data Team • 10/13/2019
The CVE-2016-8229 vulnerability represents a critical cross-site request forgery flaw discovered in Lenovo Service Bridge versions prior to 4.0, affecting systems where this service bridge is deployed. This vulnerability arises from insufficient validation of requests originating from the local network, specifically when an attacker gains access to the DHCP server that manages the network infrastructure where Lenovo Service Bridge operates. The flaw fundamentally compromises the integrity of authentication mechanisms by allowing unauthorized actions to be performed on behalf of authenticated users without their knowledge or consent. The attack vector leverages the attacker's control over the DHCP server to manipulate network communications and execute malicious requests against the vulnerable service bridge component.
The technical implementation of this vulnerability stems from the lack of proper CSRF token validation within the Lenovo Service Bridge application layer. When a user interacts with the service bridge interface, the system should validate that requests originate from legitimate sources and contain appropriate authentication tokens. However, the vulnerable implementation fails to enforce this validation, particularly in environments where the DHCP server is compromised. This weakness allows attackers to craft malicious requests that appear to originate from legitimate users within the network, bypassing standard security controls designed to prevent unauthorized modifications. The vulnerability specifically affects the service bridge's handling of network configuration changes and system management operations, where authentication tokens are either absent or insufficiently validated.
The operational impact of CVE-2016-8229 extends beyond simple privilege escalation to encompass complete system compromise within the network segment where the vulnerable Lenovo Service Bridge operates. An attacker who gains DHCP server access can manipulate network traffic to perform unauthorized actions such as changing system configurations, installing malicious software, or modifying network settings that could persist beyond the initial attack window. This vulnerability directly violates the principle of least privilege and undermines the security boundaries that separate trusted and untrusted network segments. The attack scenario becomes particularly dangerous when considering that DHCP servers often operate with elevated privileges and are frequently overlooked in security assessments, making them attractive targets for attackers seeking persistent access to network infrastructure.
Mitigation strategies for this vulnerability require a multi-layered approach that addresses both the immediate software flaw and the underlying network security weaknesses. Organizations should immediately upgrade to Lenovo Service Bridge version 4.0 or later, which incorporates proper CSRF token validation and enhanced authentication mechanisms. Network administrators must implement robust DHCP security measures including DHCP snooping, dynamic ARP inspection, and secure DHCP server configurations to prevent unauthorized access to the DHCP infrastructure. Additionally, implementing network segmentation and access control lists can limit the scope of potential attacks even if DHCP compromise occurs. This vulnerability aligns with CWE-352, which categorizes cross-site request forgery vulnerabilities, and maps to ATT&CK technique T1059.007 for execution through service execution and T1046 for network service scanning. The remediation process should include comprehensive network security audits to identify and secure all network infrastructure components that could serve as attack vectors for similar privilege escalation techniques.