CVE-2017-12334 in NX-OS
Summary
by MITRE
A vulnerability in the CLI of Cisco NX-OS System Software could allow an authenticated, local attacker to perform a command injection attack. An attacker would need valid administrator credentials to perform this exploit. The vulnerability is due to insufficient input validation of command arguments. An attacker could exploit this vulnerability by injecting crafted command arguments into a vulnerable CLI command. An exploit could allow the attacker to execute arbitrary commands as root. This vulnerability affects the following products running Cisco NX-OS System Software: Multilayer Director Switches, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 Platform Switches, Nexus 5000 Series Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules, Unified Computing System Manager. Cisco Bug IDs: CSCvf15113, CSCvf15122, CSCvf15125, CSCvf15131, CSCvf15143, CSCvg04088.
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Analysis
by VulDB Data Team • 01/25/2021
This vulnerability resides within the command line interface of Cisco NX-OS System Software, representing a critical security flaw that enables authenticated local attackers to execute arbitrary commands with root privileges. The vulnerability stems from inadequate input validation mechanisms within the CLI processing framework, creating a pathway for command injection attacks that bypass normal security controls. The flaw specifically manifests when the system fails to properly sanitize command arguments passed through the interface, allowing maliciously crafted inputs to be interpreted as executable commands rather than mere parameters. This represents a classic command injection vulnerability that operates at the operating system level, where user-supplied input directly influences system command execution without proper sanitization or validation.
The technical exploitation of this vulnerability requires an attacker to possess valid administrator credentials, establishing a privileged execution context that significantly reduces the attack surface complexity. However, the impact remains severe as the authenticated access enables the attacker to leverage the system's administrative privileges for command injection. The vulnerability affects a broad range of Cisco networking equipment including multilayer directors, various nexus series switches, unified computing system managers, and specialized line cards, indicating a widespread exposure across multiple product lines. The affected devices operate in standalone NX-OS mode, suggesting the vulnerability is not limited to specific deployment configurations or operational modes. The Cisco bug identifiers CSCvf15113 through CSCvg04088 document multiple instances of this flaw across different software versions and product variants, highlighting the systemic nature of the input validation deficiency.
The operational impact of this vulnerability extends beyond simple privilege escalation, as successful exploitation enables attackers to execute arbitrary code with the highest system privileges. This capability allows for complete system compromise, data exfiltration, network reconnaissance, and potential lateral movement within the affected network infrastructure. The vulnerability's presence in core switching equipment means that successful exploitation could disrupt network operations, compromise network security policies, and provide attackers with persistent access points. Attackers could leverage this vulnerability to install backdoors, modify network configurations, or establish covert communication channels that would be difficult to detect through standard monitoring procedures.
Mitigation strategies for this vulnerability should prioritize immediate credential management and access control measures, including implementing strong authentication protocols and monitoring for unauthorized administrative access attempts. Network segmentation and privilege separation should be enforced to limit the potential impact of successful exploitation attempts. Cisco has released patches and software updates addressing this vulnerability, which should be deployed immediately across all affected systems. Organizations should implement comprehensive monitoring for suspicious command execution patterns and establish incident response procedures specifically addressing CLI-based command injection attacks. The vulnerability aligns with CWE-77 and CWE-94 categories related to command injection and code injection flaws, and represents a technique consistent with ATT&CK tactics including privilege escalation and execution through command-line interfaces. Regular security assessments and input validation reviews should be conducted to prevent similar vulnerabilities in future system development and deployment cycles.