CVE-2016-1456 in IOS XR
Summary
by MITRE
The CLI in Cisco IOS XR 6.x through 6.0.1 allows local users to execute arbitrary OS commands in a privileged context by leveraging unspecified container access, aka Bug ID CSCuz62721.
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Analysis
by VulDB Data Team • 02/26/2019
The vulnerability described in CVE-2016-1456 represents a critical privilege escalation flaw within Cisco IOS XR software version 6.x through 6.0.1. This issue resides in the command line interface component of the operating system, which is fundamental to network device management and configuration. The vulnerability specifically affects the container access mechanisms that govern how different processes and users interact within the IOS XR environment, creating a pathway for local attackers to gain elevated privileges and execute arbitrary operating system commands.
The technical exploitation of this vulnerability leverages unspecified container access mechanisms within the IOS XR framework, allowing an attacker with local access to the device to escalate privileges from a standard user context to a privileged administrative level. This container access flaw essentially provides unauthorized code execution capabilities within the system's privileged execution environment, bypassing normal security controls and access restrictions that should normally prevent such unauthorized operations. The underlying flaw appears to stem from insufficient validation of container access permissions, enabling malicious code to be executed with elevated privileges that should be restricted to authorized administrative users only.
The operational impact of this vulnerability is severe as it allows local users to execute arbitrary OS commands with root-level privileges, potentially enabling complete system compromise. An attacker could leverage this vulnerability to install backdoors, modify system configurations, access sensitive data, or disrupt network operations entirely. The privileged execution context provides access to all system resources and network interfaces, making this vulnerability particularly dangerous for network infrastructure devices where such access could be leveraged to compromise entire network segments or establish persistent access points for further attacks.
This vulnerability aligns with CWE-269: Improper Privilege Management, which describes weaknesses related to insufficient control over access to protected resources. The flaw also maps to ATT&CK technique T1068: Exploitation for Privilege Escalation, as it provides a method for local users to escalate their privileges within the system. Organizations should consider implementing network segmentation and access controls to limit local access to critical network infrastructure devices. The recommended mitigations include applying the latest security patches from Cisco, implementing strict access controls, monitoring for unauthorized local access attempts, and conducting regular security assessments of network device configurations.
Cisco addressed this vulnerability through software updates that corrected the container access controls within the IOS XR CLI component. The patch ensures proper validation of access permissions and prevents unauthorized privilege escalation through the container mechanisms. Organizations should prioritize immediate deployment of the relevant security patches and implement comprehensive monitoring to detect any exploitation attempts. Additional defensive measures include restricting local access to network devices, implementing strong authentication mechanisms, and maintaining detailed audit logs of all system access and command execution activities to support incident response and forensic analysis efforts.