CVE-2018-15327 in BIG-IP
Summary
by MITRE
In BIG-IP 14.0.0-14.0.0.2 or 13.0.0-13.1.1.1 or Enterprise Manager 3.1.1, when authenticated administrative users run commands in the Traffic Management User Interface (TMUI), also referred to as the BIG-IP Configuration utility, restrictions on allowed commands may not be enforced.
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Analysis
by VulDB Data Team • 06/04/2023
The vulnerability identified as CVE-2018-15327 represents a critical authorization bypass flaw in F5 Networks BIG-IP application delivery controllers and Enterprise Manager systems. This issue affects specific versions including BIG-IP 14.0.0 through 14.0.0.2 and 13.0.0 through 13.1.1.1, along with Enterprise Manager 3.1.1. The vulnerability stems from insufficient input validation and command execution controls within the Traffic Management User Interface, which serves as the primary administrative interface for configuring and managing BIG-IP systems. The flaw allows authenticated administrative users to execute arbitrary commands beyond the intended restrictions imposed by the system's access controls.
The technical implementation of this vulnerability resides in the TMUI's command processing mechanisms where user inputs are not properly sanitized or validated before being passed to underlying system commands. This creates an environment where malicious command injection can occur, effectively bypassing the normal administrative command restrictions that should prevent unauthorized system operations. The vulnerability is particularly dangerous because it operates within the administrative context, meaning any authenticated user with administrative privileges can exploit this flaw to execute arbitrary code on the target system. This represents a direct violation of the principle of least privilege and demonstrates a critical failure in the system's privilege enforcement mechanisms.
From an operational perspective, this vulnerability poses significant risks to organizations relying on F5 BIG-IP systems for critical network infrastructure. Attackers who can obtain administrative credentials can leverage this flaw to gain complete control over the affected systems, potentially leading to data breaches, service disruption, and lateral movement within the network. The impact extends beyond individual system compromise as compromised BIG-IP appliances can serve as attack vectors for targeting internal network resources. Organizations may experience denial of service, data exfiltration, and complete system takeover, making this vulnerability particularly concerning for enterprise environments where these appliances are critical to network operations. The vulnerability aligns with CWE-77 and CWE-78 categories, specifically addressing command injection flaws and inadequate input validation that enable unauthorized command execution.
The exploitability of this vulnerability is enhanced by the fact that it requires only authenticated administrative access, which many organizations may not properly monitor or restrict. This means that insider threats or compromised administrative accounts can immediately leverage the vulnerability without additional reconnaissance or privilege escalation. Security professionals should consider this issue in relation to ATT&CK techniques such as T1059 Command and Scripting Interpreter and T1566 Phishing for Information, as the vulnerability enables attackers to execute arbitrary commands and potentially exfiltrate sensitive configuration data. Organizations should implement comprehensive monitoring for unusual command execution patterns, particularly those involving system-level operations that would normally be restricted in administrative contexts.
Mitigation strategies should include immediate deployment of vendor patches and updates to address the command validation flaws in the TMUI interface. Organizations should also implement strict administrative access controls, including multi-factor authentication for administrative accounts and regular audit of administrative activities. Network segmentation and monitoring of administrative sessions can help detect anomalous behavior that might indicate exploitation attempts. Additionally, implementing principle of least privilege for administrative users and conducting regular security assessments of administrative interfaces will reduce the attack surface. The vulnerability demonstrates the importance of proper input validation and command execution controls in administrative interfaces, aligning with security frameworks that emphasize the need for robust access control mechanisms and comprehensive security testing of administrative functions.