CVE-2015-4232 in NX-OS
Summary
by MITRE
Cisco NX-OS 6.2(10) on Nexus and MDS 9000 devices allows local users to execute arbitrary OS commands by entering crafted tar parameters in the CLI, aka Bug ID CSCus44856.
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Analysis
by VulDB Data Team • 05/22/2022
This vulnerability exists in Cisco NX-OS software version 6.2(10) running on Nexus and MDS 9000 series network devices. The flaw resides in the command line interface implementation where insufficient input validation allows maliciously crafted tar parameters to be executed with elevated privileges. Local authenticated users can exploit this vulnerability to execute arbitrary operating system commands on the affected devices, potentially leading to complete system compromise. The vulnerability is particularly concerning because it operates at the operating system level within the network infrastructure equipment, bypassing typical network security controls.
The technical root cause stems from improper sanitization of user inputs passed to the tar command execution functionality within the NX-OS CLI. When users enter specific tar parameters through the command line interface, the system fails to properly validate or escape these inputs before passing them to underlying operating system commands. This creates a classic command injection vulnerability where attacker-controlled data can be interpreted as shell commands. The flaw is categorized under CWE-78 as a failure to properly sanitize operating system command arguments, which directly enables arbitrary command execution. The vulnerability specifically affects the tar command processing functionality, making it a targeted injection point within the device management interface.
The operational impact of this vulnerability is severe for network infrastructure security. An attacker with local access to a compromised device can escalate privileges to system level and execute any command available to the operating system. This could enable unauthorized network reconnaissance, data exfiltration, modification of network configurations, or even use of the device as a pivot point for attacks against other network segments. The vulnerability affects critical network equipment including Nexus 7000, 9000 series switches, and MDS 9000 series storage switches, which form the backbone of many enterprise networks. The attack surface is limited to local access but represents a significant risk in environments where physical access control is inadequate or where privileged accounts are compromised. The vulnerability is particularly dangerous in data center environments where these devices are central to network operations and security.
Mitigation strategies should focus on immediate software updates to address the vulnerability through Cisco's official security patches. Organizations should implement strict access controls to limit local administrative access to these devices and enforce principle of least privilege. Network segmentation and monitoring should be enhanced to detect unauthorized local access attempts or suspicious command execution patterns. The implementation of device access logging and audit trails becomes critical for detecting exploitation attempts. Security teams should also consider network-based detection measures that monitor for unusual tar command usage patterns or command injection attempts. Additionally, regular security assessments of network infrastructure should include verification of patch compliance and configuration reviews to ensure proper access controls are in place. Organizations should also review their incident response procedures to ensure readiness for potential exploitation of this type of vulnerability, which could compromise core network infrastructure.