CVE-2018-7942 in iBMC
Summary
by MITRE
The iBMC (Intelligent Baseboard Management Controller) of some Huawei servers have an authentication bypass vulnerability. An unauthenticated, remote attacker may send some specially crafted messages to the affected products. Due to improper authentication design, successful exploit may cause some information leak.
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Analysis
by VulDB Data Team • 03/17/2023
The CVE-2018-7942 vulnerability targets the iBMC (Intelligent Baseboard Management Controller) firmware found in certain Huawei server models, representing a critical authentication bypass flaw that undermines the fundamental security architecture of remote management interfaces. This vulnerability resides within the authentication mechanism design of the iBMC system, which is responsible for providing out-of-band management capabilities for server hardware. The flaw allows an unauthenticated remote attacker to craft and send specially designed messages to the vulnerable iBMC components, effectively circumventing the intended authentication requirements that should normally prevent unauthorized access to management functions. The vulnerability stems from improper authentication design patterns where the system fails to properly validate incoming requests, creating a pathway for malicious actors to gain unauthorized access to sensitive management interfaces without requiring valid credentials.
The technical exploitation of this vulnerability occurs through carefully constructed network messages that exploit weaknesses in the iBMC's message processing and authentication validation logic. When an attacker sends these crafted messages, the system's authentication mechanism fails to properly verify the legitimacy of the request, allowing the malicious input to be processed as if it were from an authenticated user. This authentication bypass enables attackers to potentially access sensitive information stored within the iBMC, including system configuration details, user credentials, and other management data that should remain protected. The vulnerability's remote nature means that attackers can exploit it from outside the local network perimeter, significantly expanding the attack surface and reducing the effectiveness of traditional network-based security controls. The improper authentication design creates a persistent security gap that can be leveraged by attackers who may not have physical access to the target systems.
The operational impact of this vulnerability extends beyond simple information disclosure, as it fundamentally compromises the security posture of affected Huawei server deployments. Organizations relying on iBMC for remote server management face significant risks including unauthorized access to critical infrastructure, potential data breaches, and the possibility of attackers using the compromised management interface as a foothold for further attacks within the network. The vulnerability affects the integrity and confidentiality of the server management plane, potentially allowing attackers to modify system configurations, extract sensitive data, or even disable security features. This type of vulnerability is particularly concerning in enterprise environments where servers are often managed remotely and where the iBMC provides critical access to system monitoring, configuration, and maintenance functions. The remote exploit capability means that attackers can target these vulnerabilities from anywhere on the internet, making traditional perimeter-based security measures ineffective against this threat.
Mitigation strategies for CVE-2018-7942 should focus on immediate patching of affected iBMC firmware versions, as Huawei has released security updates to address the authentication bypass vulnerability. Organizations should implement network segmentation to isolate management interfaces from general network traffic, employ network monitoring to detect unusual authentication patterns, and conduct regular security assessments of their remote management infrastructure. The vulnerability aligns with CWE-287, which describes improper authentication issues in software systems, and represents a clear violation of the principle of least privilege in system design. From an ATT&CK framework perspective, this vulnerability maps to techniques involving initial access through network service exploitation and privilege escalation via management interface compromise, making it a significant threat vector for attackers seeking persistent access to enterprise infrastructure. Organizations should also consider implementing multi-factor authentication mechanisms for management interfaces, regularly reviewing access logs for suspicious activity, and maintaining updated inventories of all iBMC-enabled devices within their network infrastructure to ensure comprehensive protection against similar vulnerabilities.