CVE-2023-20153 in Identity Services Engine
Summary
by MITRE • 04/05/2023
Multiple vulnerabilities in specific Cisco Identity Services Engine (ISE) CLI commands could allow an authenticated, local attacker to perform command injection attacks on the underlying operating system and elevate privileges to root. To exploit these vulnerabilities, an attacker must have valid Administrator privileges on the affected device. These vulnerabilities are due to insufficient validation of user-supplied input. An attacker could exploit these vulnerabilities by submitting a crafted CLI command. A successful exploit could allow the attacker to elevate privileges to root.
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Analysis
by VulDB Data Team • 08/25/2025
The Cisco Identity Services Engine (ISE) represents a critical component in enterprise network security infrastructure, serving as a centralized policy enforcement point that manages network access control and identity verification. These vulnerabilities reside within the command line interface implementation of the ISE platform, specifically targeting the input validation mechanisms that govern administrative command processing. The affected system operates on a Linux-based operating system where CLI commands are processed through a shell interface, creating a potential attack surface where malicious input could be interpreted as system commands. The vulnerabilities are particularly concerning as they exist within the privileged administrative interface, meaning that successful exploitation requires only legitimate administrative credentials rather than additional reconnaissance or initial access vectors. This characteristic significantly reduces the attack complexity and increases the potential impact of these flaws within enterprise environments where administrative access is typically restricted but still present.
The technical flaw manifests as insufficient input validation within the CLI command processing pipeline, creating a classic command injection vulnerability pattern that aligns with CWE-77 and CWE-89 classifications. When administrators submit commands through the CLI interface, the system fails to properly sanitize or validate user-supplied input before processing, allowing maliciously crafted commands to bypass normal parsing mechanisms. This weakness enables an attacker with administrative privileges to inject arbitrary shell commands that are subsequently executed with the privileges of the underlying operating system process. The vulnerability specifically affects the way the system handles certain CLI commands, where input strings are concatenated with system commands without proper escaping or sanitization, creating opportunities for command concatenation attacks. The injection occurs at the shell level where the system interprets user input as both command parameters and executable code, allowing for arbitrary command execution.
The operational impact of these vulnerabilities extends beyond simple privilege escalation to encompass complete system compromise and potential data exfiltration. Successful exploitation allows an attacker to gain root-level access to the underlying operating system, enabling them to modify system files, install persistent backdoors, access sensitive network data, and potentially pivot to other systems within the network perimeter. The elevated privileges provide access to all network access control policies, user credentials stored in the ISE database, and potentially sensitive network infrastructure information. This compromise represents a significant threat to enterprise security posture as the ISE platform typically serves as a central hub for network access control, making it a prime target for attackers seeking to maintain persistent access and expand their network foothold. The attack vector requires only legitimate administrative credentials, which means that credential theft, social engineering, or insider threats could easily lead to exploitation without additional attack surface requirements.
Mitigation strategies should focus on immediate patch deployment as the primary defense mechanism, following Cisco's security advisory releases and applying the relevant software updates that address the input validation deficiencies. Network segmentation and least privilege principles should be enforced to limit administrative access to only necessary personnel and systems, reducing the potential attack surface for these vulnerabilities. Monitoring and logging of CLI activities should be enhanced to detect anomalous command patterns that might indicate exploitation attempts, particularly focusing on command sequences that include unusual parameter combinations or command concatenation patterns. The implementation of privileged access management solutions can help reduce the risk of credential compromise and limit the scope of potential exploitation. Additionally, regular security assessments and vulnerability scanning should be conducted to identify similar input validation weaknesses in other network infrastructure components, as these vulnerabilities often stem from common coding practices that may exist across multiple systems within an organization's attack surface.