CVE-2022-20681 in IOS XE
Summary
by MITRE • 04/15/2022
A vulnerability in the CLI of Cisco IOS XE Software for Cisco Catalyst 9000 Family Switches and Cisco Catalyst 9000 Family Wireless Controllers could allow an authenticated, local attacker to elevate privileges to level 15 on an affected device. This vulnerability is due to insufficient validation of user privileges after the user executes certain CLI commands. An attacker could exploit this vulnerability by logging in to an affected device as a low-privileged user and then executing certain CLI commands. A successful exploit could allow the attacker to execute arbitrary commands with level 15 privileges on the affected device.
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Analysis
by VulDB Data Team • 04/20/2022
This vulnerability resides within the command line interface of Cisco IOS XE Software operating on Cisco Catalyst 9000 family switches and wireless controllers, representing a critical privilege escalation flaw that directly impacts network infrastructure security. The vulnerability stems from inadequate privilege validation mechanisms that fail to properly enforce access controls after specific CLI commands are executed, creating a pathway for authenticated local attackers to gain elevated system privileges. The affected devices operate under a privilege level system where level 15 represents the highest administrative access, effectively granting full control over the network device's operational capabilities.
The technical flaw manifests as a failure in the software's privilege checking logic during command execution sequences, specifically when certain administrative commands are processed. This weakness allows an attacker with minimal user credentials to exploit the system's trust model by executing a series of carefully crafted CLI commands that bypass normal privilege validation checks. The vulnerability is particularly concerning because it requires only local authentication access, meaning an attacker who has already gained initial access to the device can escalate their privileges without requiring additional credentials or external attack vectors. This flaw operates under the CWE-284 access control weakness category, specifically addressing improper privilege management within network device operating systems.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete administrative control over affected network infrastructure. Once elevated to level 15 privileges, an attacker can modify device configurations, access sensitive network data, implement malicious network policies, and potentially use the compromised device as a pivot point for further attacks within the network. This vulnerability directly maps to several ATT&CK techniques including privilege escalation through command execution and lateral movement by leveraging administrative access to control network infrastructure. The implications are severe for network security posture, as it undermines the fundamental security model of network devices that rely on proper privilege separation to maintain operational integrity.
Mitigation strategies should focus on immediate software updates and patches provided by Cisco to address the privilege validation flaw, while also implementing robust network access controls to limit local administrative access. Organizations should conduct comprehensive vulnerability assessments to identify all affected devices and implement monitoring solutions to detect suspicious command execution patterns. Network segmentation and least privilege principles should be enforced to minimize the potential impact of such vulnerabilities, while regular security audits should verify that privilege escalation attempts are properly logged and investigated. The vulnerability demonstrates the critical importance of maintaining current security patches and implementing proper access control measures in network infrastructure devices.