CVE-2024-20439 in Smart License Utility
Summary
by MITRE • 09/04/2024
A vulnerability in Cisco Smart Licensing Utility (CSLU) could allow an unauthenticated, remote attacker to log into an affected system by using a static administrative credential. This vulnerability is due to an undocumented static user credential for an administrative account. An attacker could exploit this vulnerability by using the static credentials to login to the affected system. A successful exploit could allow the attacker to login to the affected system with administrative rights over the CSLU application API.
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Analysis
by VulDB Data Team • 10/28/2025
The vulnerability identified as CVE-2024-20439 represents a critical security flaw within Cisco Smart Licensing Utility (CSLU) that exposes systems to unauthorized remote access through the exploitation of a hardcoded administrative credential. This weakness fundamentally undermines the security posture of affected Cisco devices by providing an unauthenticated pathway for attackers to gain administrative privileges without requiring legitimate authentication mechanisms. The vulnerability stems from the inclusion of a static, undocumented administrative account within the CSLU application that remains accessible throughout the system's operational lifecycle, creating a persistent backdoor that persists across system updates and reboots.
The technical implementation of this vulnerability aligns with CWE-798, which specifically addresses the use of hard-coded credentials in software applications. The flaw manifests as an insecure configuration where the CSLU application contains a pre-defined administrative account with a static password that is not properly secured or obscured from potential attackers. This hardcoded credential allows remote exploitation without the need for any authentication challenges, privilege escalation techniques, or complex attack vectors. The vulnerability specifically affects the application programming interface of the CSLU utility, which serves as the administrative interface for managing licensing functions within Cisco environments.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it provides attackers with complete administrative control over the CSLU application and potentially broader system access depending on the deployment architecture. Attackers can leverage this vulnerability to manipulate licensing configurations, potentially disabling licensing enforcement mechanisms, modifying license terms, or gaining access to sensitive licensing information. The remote nature of the exploit means that attackers can target affected systems from anywhere on the network without requiring physical access or prior compromise of other system components, making this vulnerability particularly dangerous in enterprise environments where multiple Cisco devices may be exposed to external networks.
The security implications of this vulnerability align with several ATT&CK framework techniques including T1078 for valid accounts and T1046 for network service scanning, as attackers can use this credential to establish persistent access and potentially expand their attack surface. Organizations should immediately implement mitigations including disabling unused administrative accounts, implementing network segmentation to restrict access to CSLU interfaces, and conducting comprehensive vulnerability assessments to identify all affected systems. The remediation process should involve updating to the latest Cisco software releases that address this hardcoded credential issue, implementing strong access controls for remaining administrative accounts, and establishing monitoring procedures to detect unauthorized access attempts to administrative interfaces. Without immediate remediation, this vulnerability could enable attackers to establish persistent backdoors within network infrastructure and potentially facilitate further attacks against other system components within the affected environments.