CVE-2023-20231 in IOS XE
Summary
by MITRE • 10/25/2023
A vulnerability in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker to perform an injection attack against an affected device.
This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending crafted input to the web UI. A successful exploit could allow the attacker to execute arbitrary Cisco IOS XE Software CLI commands with level 15 privileges.
Note: This vulnerability is exploitable only if the attacker obtains the credentials for a Lobby Ambassador account. This account is not configured by default.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 10/25/2023
This vulnerability exists within the web user interface of Cisco IOS XE Software, representing a critical security weakness that enables authenticated remote code execution. The flaw stems from inadequate input validation mechanisms within the web UI components, creating an injection attack vector that can be exploited by malicious actors who have already obtained legitimate credentials. The vulnerability specifically affects the processing of user input within the web interface, where insufficient sanitization allows crafted payloads to be interpreted as command instructions rather than simple data input. This represents a classic command injection vulnerability that can be categorized under CWE-77 and aligns with ATT&CK technique T1059.004 for command and scripting interpreter. The security implications are severe as the vulnerability allows execution of arbitrary commands with the highest privilege level available within the IOS XE environment.
The technical exploitation requires an attacker to first gain access to a Lobby Ambassador account, which serves as a privileged administrative role within the Cisco IOS XE system. This account type is not enabled by default, making the initial compromise more challenging but not impossible. The attack vector operates through the web UI interface, where the attacker can submit malicious input that bypasses normal validation checks. The vulnerability's impact extends beyond simple data manipulation as it allows execution of Cisco IOS XE Software CLI commands with level 15 privileges, which represents the highest administrative access level within the IOS system. This privilege level provides complete control over the device, including the ability to modify configurations, access sensitive data, and potentially use the compromised device as a pivot point for further attacks within the network. The exploitation process involves crafting specific input sequences that are then interpreted by the underlying system as executable commands rather than user data.
The operational impact of this vulnerability extends beyond the immediate device compromise, as it provides attackers with extensive control over network infrastructure. Once successfully exploited, an attacker can manipulate network configurations, disable security features, and potentially use the compromised device to launch attacks against other systems within the network. The vulnerability's requirement for a pre-existing Lobby Ambassador account credential means that attackers must first overcome authentication barriers, but this does not prevent the exploitation of the underlying injection flaw. The presence of this vulnerability in the web UI interface means that attacks can be conducted remotely without requiring physical access to the device, making it particularly dangerous for organizations that rely on web-based management interfaces. Organizations may face significant operational disruption, data breaches, and potential compliance violations if this vulnerability is exploited, as the attacker gains complete administrative control over the affected network device.
Mitigation strategies for this vulnerability should focus on multiple layers of security controls to address both the authentication requirements and the underlying injection flaw. Organizations should immediately review and secure all administrative accounts, particularly those that are not enabled by default, ensuring that only authorized personnel have access to these privileged roles. Implementing strong access controls and multi-factor authentication for all administrative interfaces is crucial, as is regular monitoring of administrative account usage for suspicious activities. Network segmentation and least privilege principles should be enforced to limit the potential impact if an account is compromised. Cisco has released patches and updates to address this vulnerability, which should be deployed immediately across all affected systems. Additionally, organizations should implement web application firewalls and input validation controls to detect and prevent injection attempts, and conduct regular security assessments to identify and remediate similar vulnerabilities in other network components. The vulnerability also highlights the importance of proper input validation in all user interface components and demonstrates the critical need for continuous security testing and code review processes.