CVE-2017-12329 in Firepower Extensible Operating System
Summary
by MITRE
A vulnerability in the CLI of Cisco Firepower Extensible Operating System (FXOS) and NX-OS System Software could allow an authenticated, local attacker to perform a command injection attack. The vulnerability is due to insufficient input validation of command arguments to the CLI parser. 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 at the user's privilege level. On products that support multiple virtual device contexts (VDCs), this vulnerability could allow the attacker to execute commands at the user's privilege level outside the user's environment. This vulnerability affects the following products running Cisco FXOS or NX-OS System Software: Firepower 4100 Series Next-Generation Firewall, Firepower 9300 Security Appliance, Multilayer Director Switches, Nexus 1000V Series 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: CSCve51700, CSCve93833, CSCve93860, CSCve93863, CSCve93864, CSCve93880.
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Analysis
by VulDB Data Team • 01/25/2021
The vulnerability identified as CVE-2017-12329 represents a critical command injection flaw within the command line interface of Cisco's Firepower Extensible Operating System and NX-OS System Software. This weakness stems from inadequate input validation mechanisms within the CLI parser, creating an exploitable pathway for authenticated local attackers to execute arbitrary commands with the privileges of the authenticated user. The vulnerability specifically targets the parsing of command arguments, where insufficient sanitization allows malicious inputs to bypass normal validation checks and be interpreted as executable commands rather than simple parameters.
The technical exploitation of this vulnerability occurs through the injection of crafted command arguments into vulnerable CLI commands, enabling attackers to manipulate the system's command processing behavior. This flaw operates at the privilege level of the authenticated user, meaning that an attacker must first establish legitimate credentials to access the system before exploiting the vulnerability. However, the impact extends beyond individual user privileges, particularly on devices supporting multiple virtual device contexts, where attackers could potentially execute commands outside their designated environment, compromising the isolation between different VDCs and potentially affecting multiple logical segments within a single physical device.
The operational implications of this vulnerability are severe given the widespread deployment of affected Cisco products across enterprise networks. The vulnerability affects a broad range of network infrastructure devices including next-generation firewalls, switching platforms, and unified computing systems, making it a significant threat to network security posture. Attackers could leverage this vulnerability to escalate privileges, install backdoors, modify system configurations, or exfiltrate sensitive information from network devices. The fact that this vulnerability affects multiple product lines including the Firepower 4100 series, Nexus 7000 series, and 9000 series switches demonstrates the widespread nature of the flaw and its potential to impact critical network infrastructure components.
Security practitioners should note that this vulnerability aligns with CWE-74 and CWE-77 categories, representing weaknesses in input validation and command injection respectively. The attack pattern corresponds to techniques described in the MITRE ATT&CK framework under the T1059.001 sub-technique for Command and Scripting Interpreter, and T1068 for Exploitation for Privilege Escalation. The vulnerability's exploitation requires local access and authentication, making it less likely to be exploited remotely but still poses significant risk in environments where physical or logical access to network devices is possible. Organizations should implement immediate mitigations including applying the relevant Cisco security patches, reviewing access controls to limit local administrative access, and monitoring for suspicious CLI activity that might indicate exploitation attempts.
The affected product portfolio spans Cisco's entire line of network security and switching equipment, from entry-level switches to high-end security appliances, indicating that organizations with legacy systems may be particularly vulnerable. The vulnerability's persistence across multiple generations of hardware suggests that organizations should conduct comprehensive inventory assessments to identify all affected devices and prioritize patching efforts based on risk exposure. The presence of multiple Cisco bug IDs (CSCve51700 through CSCve93880) indicates that this vulnerability was recognized across various product lines and affected different software versions, requiring coordinated patch management across the entire network infrastructure to ensure complete protection against this threat.