CVE-2015-6480 in OnCell Central Manager
Summary
by MITRE
The MessageBrokerServlet servlet in Moxa OnCell Central Manager before 2.2 does not require authentication, which allows remote attackers to obtain administrative access via a command, as demonstrated by the addUserAndGroup action.
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Analysis
by VulDB Data Team • 06/20/2018
The vulnerability identified as CVE-2015-6480 resides within the MessageBrokerServlet component of Moxa OnCell Central Manager software prior to version 2.2. This represents a critical authentication bypass flaw that fundamentally undermines the security posture of the affected system. The vulnerability specifically affects the servlet's handling of administrative commands, creating an unauthorized access vector that can be exploited by remote attackers without any legitimate credentials.
The technical implementation of this flaw stems from the MessageBrokerServlet's failure to enforce proper authentication mechanisms before processing administrative requests. When attackers send malicious payloads to the servlet, particularly targeting the addUserAndGroup action, the system processes these commands without verifying the identity or authorization status of the requesting entity. This authentication gap creates a direct pathway for unauthorized users to execute administrative functions that should only be accessible to authorized administrators. The vulnerability operates at the application layer and leverages the servlet's design flaw to bypass the normal authentication flow that would typically validate user credentials and permissions before executing privileged operations.
The operational impact of this vulnerability is severe and multifaceted, as it allows remote attackers to assume full administrative control over the affected system. Successful exploitation enables attackers to add new users and groups to the system, effectively granting them persistent access and the ability to modify system configurations. This administrative access can be leveraged to establish backdoors, modify network settings, compromise data integrity, and potentially escalate privileges to gain control over connected devices within the Moxa OnCell network infrastructure. The remote nature of the exploit means that attackers can target the system from anywhere on the internet without requiring physical access or local network presence, making the vulnerability particularly dangerous for industrial control systems and network management platforms.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-287, which addresses improper authentication issues in software systems. The flaw demonstrates a classic case of insufficient authorization controls where the system fails to properly validate user identities before granting access to sensitive functions. The attack pattern corresponds to techniques described in the MITRE ATT&CK framework under the T1078 category, specifically targeting legitimate credentials and privileges to gain unauthorized access to systems. Organizations implementing Moxa OnCell Central Manager should consider this vulnerability as part of their broader security posture assessment, particularly in environments where industrial control systems are deployed and where network segmentation is critical for operational technology security.
The recommended mitigations for this vulnerability include immediate deployment of the vendor-provided security patches for Moxa OnCell Central Manager version 2.2 or later, which address the authentication bypass flaw through proper access control implementation. Network administrators should also implement additional security controls such as firewall rules to restrict access to the affected servlet endpoints, network segmentation to isolate the management interface, and monitoring solutions to detect unusual administrative activities. Regular security assessments and vulnerability scanning should be conducted to identify similar authentication bypass issues in other components of the network infrastructure, while also implementing principle of least privilege access controls to minimize the potential impact of any future similar vulnerabilities.