CVE-2023-20193 in Identity Services Engine
Summary
by MITRE • 09/07/2023
A vulnerability in the Embedded Service Router (ESR) of Cisco ISE could allow an authenticated, local attacker to read, write, or delete arbitrary files on the underlying operating system and escalate their privileges to root. To exploit this vulnerability, an attacker must have valid Administrator-level privileges on the affected device. This vulnerability is due to improper privilege management in the ESR console. An attacker could exploit this vulnerability by sending a crafted request to an affected device. A successful exploit could allow the attacker to elevate their privileges to root and read, write, or delete arbitrary files from the underlying operating system of the affected device. Note: The ESR is not enabled by default and must be licensed. To verify the status of the ESR in the Admin GUI, choose Administration > Settings > Protocols > IPSec.
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Analysis
by VulDB Data Team • 10/02/2023
This vulnerability exists within the Embedded Service Router component of Cisco Identity Services Engine (ISE) platforms, representing a critical privilege escalation flaw that can be exploited by authenticated attackers with administrator-level credentials. The issue stems from inadequate privilege management controls within the ESR console implementation, creating a path for malicious actors to bypass normal access controls and gain full system root privileges. The vulnerability specifically affects the ESR functionality which serves as an embedded routing service within the ISE platform, providing network access control and policy enforcement capabilities. The ESR component operates with elevated privileges but fails to properly validate or restrict the permissions of authenticated administrative users who attempt to interact with its console interface.
The technical exploitation mechanism involves sending specially crafted requests to the affected device through the ESR console interface, which allows an authenticated administrator to perform operations that should normally be restricted to system-level processes. This flaw essentially creates a backdoor path where administrative users can manipulate the underlying operating system files directly, enabling them to read sensitive data, modify system configurations, delete critical files, or execute arbitrary code with the highest possible privileges. The vulnerability's impact extends beyond simple privilege escalation as it provides complete system compromise capabilities, allowing attackers to establish persistent access and potentially exfiltrate data from the entire network infrastructure controlled by the ISE platform. This represents a significant deviation from the principle of least privilege, where the system fails to properly enforce access controls for administrative functions.
The operational impact of this vulnerability is severe for organizations relying on Cisco ISE for network access control and identity management. Successful exploitation could enable attackers to gain complete control over the network infrastructure, potentially allowing them to manipulate access policies, redirect network traffic, or establish persistent backdoors for future access. Organizations with compromised ISE systems could face widespread network disruption, data breaches, and loss of network visibility. The vulnerability's discovery highlights critical flaws in the privilege management architecture of enterprise security platforms, where administrative interfaces fail to properly isolate and restrict user capabilities. This issue particularly affects organizations that have licensed and enabled the ESR functionality, as the vulnerability requires the component to be active and configured for exploitation to occur. The default disablement of ESR in Cisco ISE installations provides some mitigation, but organizations must verify their configuration through the Administration > Settings > Protocols > IPSec path in the Admin GUI to ensure proper security posture.
Organizations should implement immediate mitigations including verifying that ESR is disabled on systems where it is not required, applying the latest Cisco security patches and updates, and monitoring for unauthorized access attempts to the ESR console. Network segmentation and access control measures should be enhanced to limit administrative access to only necessary personnel, while implementing robust audit logging to detect suspicious activities. The vulnerability aligns with CWE-276 (Incorrect Permission Assignment) and CWE-284 (Improper Access Control) categories, and represents a technique consistent with ATT&CK tactics including privilege escalation and persistence. Security teams should conduct comprehensive vulnerability assessments to identify all instances of affected Cisco ISE deployments and ensure proper configuration management practices are enforced. Regular security monitoring and incident response procedures should be strengthened to detect and respond to potential exploitation attempts of this vulnerability. The incident also underscores the importance of maintaining up-to-date security controls and the necessity of validating security configurations through regular audits and penetration testing activities.