CVE-2015-6424 in Application Policy Infrastructure Controller
Summary
by MITRE
The boot manager in Cisco Application Policy Infrastructure Controller (APIC) 1.1(0.920a) allows local users to bypass intended access restrictions and obtain single-user-mode root access via unspecified vectors, aka Bug ID CSCuu83985.
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Analysis
by VulDB Data Team • 07/01/2022
The vulnerability identified as CVE-2015-6424 affects the boot manager component of Cisco's Application Policy Infrastructure Controller version 1.1(0.920a), representing a critical security flaw that undermines the system's integrity and access controls. This issue specifically targets the boot process mechanism that governs how the APIC system initializes and authenticates users during startup operations. The vulnerability enables local attackers who possess physical or administrative access to the system to circumvent established security restrictions and escalate their privileges to root level access within the single-user mode environment. This represents a fundamental breakdown in the system's privilege separation mechanisms, where the intended security boundaries between normal operational modes and restricted single-user modes have been successfully bypassed. The affected system operates within enterprise network infrastructure environments where the APIC serves as a critical controller for application policy management and network segmentation.
The technical flaw manifests through unspecified vectors within the boot manager's authentication and authorization processes, allowing attackers to manipulate the system initialization sequence to gain root access without proper credentials or authorization. This vulnerability operates at the system level during boot operations, where the normal security checks that should prevent unauthorized access to single-user mode are either bypassed or rendered ineffective. The attack vector likely involves manipulating boot parameters, exploiting timing vulnerabilities in the authentication process, or leveraging weaknesses in the boot manager's validation logic that fails to properly verify the legitimacy of access requests during system startup. According to CWE classification, this vulnerability aligns with CWE-284 Access Control Issues, specifically related to improper privileges and insufficient access control mechanisms during system initialization phases. The flaw represents a privilege escalation vulnerability that operates at the operating system level, where the attacker's ability to obtain root access through single-user mode bypasses standard security controls that should protect the system's core functionality.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete control over the APIC system's core functions and access to all managed network policies and configurations. Once root access is obtained through single-user mode, attackers can modify system files, access sensitive network policy information, manipulate application delivery controllers, and potentially compromise the entire network infrastructure that relies on the APIC for policy enforcement. The vulnerability affects enterprise environments where network segmentation, application delivery, and policy enforcement are critical for maintaining security boundaries and protecting sensitive data flows. The attack scenario involves a local attacker who has already gained access to the system through other means or who can physically access the device, then leverages this vulnerability to escalate privileges and gain unrestricted access to the system's core functionality. This creates a significant risk for organizations that depend on APIC for network policy management, as the compromise of a single controller can potentially affect the entire network infrastructure that relies on its policy enforcement capabilities.
Organizations should implement immediate mitigations including applying Cisco's security patches and updates specifically designed to address this vulnerability, ensuring proper access controls are enforced at the physical and logical levels, and implementing monitoring for unauthorized boot sequence modifications. The remediation process should involve verifying the system's integrity through checksum validation and ensuring that boot parameters cannot be modified without proper authorization. Network administrators should also implement strict physical security measures for APIC devices, as this vulnerability requires local access to exploit effectively. The vulnerability's impact is further amplified by its potential to serve as a stepping stone for more sophisticated attacks, where the root access obtained can be used to establish persistent access or to move laterally within the network infrastructure. According to ATT&CK framework, this vulnerability maps to privilege escalation techniques and can be leveraged as part of broader attack chains where initial access is used to gain root privileges for more extensive system compromise. Organizations should also conduct comprehensive security assessments of their APIC deployments to identify any other potential access control weaknesses and ensure proper network segmentation to limit the potential impact of such vulnerabilities.