CVE-2017-6623 in Policy Suite CPS
Summary
by MITRE
A vulnerability in a script file that is installed as part of the Cisco Policy Suite (CPS) Software distribution for the CPS appliance could allow an authenticated, local attacker to escalate their privilege level to root. The vulnerability is due to incorrect sudoers permissions on the script file. An attacker could exploit this vulnerability by authenticating to the device and providing crafted user input at the CLI, using this script file to escalate their privilege level and execute commands as root. A successful exploit could allow the attacker to acquire root-level privileges and take full control of the appliance. The user has to be logged-in to the device with valid credentials for a specific set of users. The Cisco Policy Suite application is vulnerable when running software versions 10.0.0, 10.1.0, or 11.0.0. Cisco Bug IDs: CSCvc07366.
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Analysis
by VulDB Data Team • 12/25/2020
The vulnerability described in CVE-2017-6623 represents a critical privilege escalation flaw within Cisco Policy Suite (CPS) software versions 10.0.0, 10.1.0, and 11.0.0. This issue specifically targets the CPS appliance configuration where improper sudoers permissions have been implemented on a particular script file. The vulnerability exists in the authentication and authorization mechanisms of the system, creating an exploitable condition that allows local authenticated users to gain root-level privileges. The flaw demonstrates a clear breakdown in the principle of least privilege, where the script file has been configured with overly permissive access controls that should not be available to regular authenticated users. This misconfiguration creates a pathway for attackers to elevate their privileges without requiring additional authentication mechanisms or complex exploitation techniques.
The technical exploitation of this vulnerability requires an authenticated user with valid credentials to access the device's command-line interface and interact with the specifically crafted script file. The attacker must utilize the vulnerable script in a way that leverages the incorrect sudoers permissions to execute commands with root privileges. This process typically involves providing crafted input through the CLI that triggers the vulnerable script, which then executes with elevated privileges due to the improper permissions. The vulnerability is classified as a local privilege escalation issue where the attacker's initial access level is insufficient to perform system-level operations, but the flawed sudoers configuration allows them to bypass normal access controls and execute commands with root privileges. The flaw directly relates to CWE-276, which addresses incorrect permissions for critical resources, and demonstrates how improper access control configuration can lead to complete system compromise.
The operational impact of this vulnerability is severe and potentially catastrophic for organizations relying on Cisco Policy Suite appliances. Successful exploitation provides attackers with complete administrative control over the affected appliance, enabling them to modify system configurations, access sensitive data, install malicious software, and potentially use the compromised appliance as a pivot point for attacking other systems within the network. The vulnerability essentially transforms any authenticated user account into a potential root-level threat, eliminating the need for additional attack vectors or credential compromise. Organizations may experience unauthorized access to network policies, configuration changes, data exfiltration, and service disruption. The attack requires minimal sophistication beyond having valid credentials, making it particularly dangerous as it can be exploited by insiders or external attackers who have obtained legitimate user credentials.
Mitigation strategies for CVE-2017-6623 should focus on immediate remediation through official Cisco software updates and patches addressing the specific sudoers permission configuration issue. Organizations must ensure that all affected Cisco Policy Suite appliances are updated to versions that resolve the vulnerability. Additionally, network segmentation and access control measures should be implemented to limit the number of users with valid credentials and reduce the attack surface. The principle of least privilege should be enforced by reviewing and restricting sudoers permissions for all script files and system utilities. Security monitoring should be enhanced to detect unusual command execution patterns and privilege escalation attempts. Network administrators should consider implementing multi-factor authentication for administrative access and regularly audit user permissions to ensure that only authorized personnel have access to critical system components. The vulnerability highlights the importance of proper access control configuration and the need for regular security assessments of system permissions and privilege levels within enterprise network infrastructure.