CVE-2018-7949 in Server
Summary
by MITRE
The iBMC (Intelligent Baseboard Management Controller) of some Huawei servers have a privilege escalation vulnerability. A remote attacker may send some specially crafted login messages to the affected products. Due to improper authentication design, successful exploit enables low privileged users to get or modify passwords of highly privileged users.
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Analysis
by VulDB Data Team • 03/19/2023
The CVE-2018-7949 vulnerability represents a critical privilege escalation flaw within Huawei's iBMC (Intelligent Baseboard Management Controller) systems, which serve as the foundational management infrastructure for numerous enterprise server platforms. This vulnerability resides in the authentication mechanism design of the iBMC firmware, specifically within the login message processing functionality that governs user access controls and privilege levels. The flaw allows remote attackers to manipulate the authentication flow through carefully crafted network messages, effectively bypassing the intended security controls that should prevent unauthorized privilege elevation. The vulnerability impacts multiple Huawei server models that utilize the iBMC management controller, creating widespread exposure across enterprise data centers and cloud infrastructure deployments where these systems are prevalent.
The technical exploitation of this vulnerability stems from improper authentication design patterns within the iBMC's message handling architecture, which fails to properly validate the authenticity and authorization levels of incoming login requests. Attackers can craft specially formatted login messages that exploit the lack of proper input validation and privilege verification mechanisms within the authentication subsystem. This flaw operates at the protocol level of the iBMC's management interface, allowing an attacker with minimal privileges to manipulate the authentication process and subsequently gain access to administrative accounts with elevated permissions. The vulnerability specifically targets the password modification functionality, enabling attackers to not only escalate their privileges but also to modify the credentials of highly privileged users, potentially compromising the entire management infrastructure. This represents a fundamental failure in the principle of least privilege enforcement and demonstrates a critical weakness in the iBMC's access control implementation.
The operational impact of CVE-2018-7949 extends far beyond simple privilege escalation, as it fundamentally compromises the security posture of affected Huawei server environments. Successful exploitation creates a persistent backdoor for attackers to maintain long-term access to critical management interfaces, enabling them to monitor system activities, modify configurations, and potentially exfiltrate sensitive data from the management plane. The vulnerability's remote nature means that attackers can exploit it from anywhere on the network without requiring physical access to the servers, making it particularly dangerous in cloud and data center environments where management interfaces are often exposed to external networks. Organizations utilizing affected Huawei servers face significant risk of unauthorized access to their entire server fleet, as the iBMC management controller typically provides access to system configuration, firmware updates, and other critical administrative functions that are essential for maintaining system integrity and security. This vulnerability directly violates the security principle of separation of privileges and creates opportunities for attackers to escalate their compromise into full system control.
Mitigation strategies for CVE-2018-7949 should encompass both immediate defensive measures and long-term architectural improvements to prevent similar vulnerabilities in the future. Organizations must implement network segmentation to isolate iBMC management interfaces from general network traffic, ensuring that only authorized management systems can access these critical endpoints. Access control lists and firewall rules should be configured to restrict access to iBMC ports to known management stations only, while implementing multi-factor authentication for all administrative access. The most effective immediate solution involves applying the official Huawei security patches that address the authentication design flaw, though organizations should also consider disabling unused iBMC management interfaces when not required for operational purposes. This vulnerability aligns with CWE-284 (Improper Access Control) and represents a clear violation of the principle of least privilege, while its exploitation techniques correspond to ATT&CK tactics including privilege escalation and persistence. Organizations should conduct comprehensive vulnerability assessments of their entire server infrastructure to identify all affected iBMC implementations and ensure that management interfaces are properly secured through network segmentation, access control enforcement, and regular security updates to prevent exploitation of similar authentication bypass vulnerabilities in the future.