CVE-2018-5544 in BIG-IP APM
Summary
by MITRE
When the F5 BIG-IP APM 13.0.0-13.1.1 or 12.1.0-12.1.3 renders certain pages (pages with a logon agent or a confirm box), the BIG-IP APM may disclose configuration information such as partition and agent names via URI parameters.
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Analysis
by VulDB Data Team • 04/27/2023
The vulnerability identified as CVE-2018-5544 affects F5 BIG-IP Access Policy Manager (APM) versions 12.1.0 through 12.1.3 and 13.0.0 through 13.1.1, representing a significant information disclosure flaw that undermines the security posture of enterprise network access control systems. This vulnerability manifests when the APM component processes specific web pages that contain logon agents or confirmation boxes, creating an unintended data leakage channel that exposes sensitive configuration details to unauthorized parties. The flaw operates at the application layer and specifically targets the way the system handles URI parameters during page rendering processes, making it particularly dangerous for organizations relying on F5 BIG-IP appliances for secure remote access management.
The technical implementation of this vulnerability stems from improper handling of URI parameters within the APM's web interface rendering mechanism. When users navigate to pages containing logon agents or confirmation boxes, the system inadvertently includes partition names and agent identifiers as query parameters in the URI structure. This occurs because the APM component fails to properly sanitize or filter the URI parameters before rendering the web content, allowing configuration metadata to be exposed through the URL path. The vulnerability is classified under CWE-200 Information Exposure, which specifically addresses the unintentional disclosure of information that could aid attackers in understanding system architecture and configuration details. This information disclosure creates a foundation for more sophisticated attacks by providing attackers with insights into the internal structure of the network access control system.
The operational impact of CVE-2018-5544 extends beyond simple information leakage, as the exposed partition and agent names provide attackers with critical architectural intelligence for subsequent exploitation attempts. An attacker who intercepts these URIs can gain knowledge about the organization's network segmentation strategy, access control policies, and the specific authentication mechanisms deployed within the BIG-IP environment. This information can be leveraged to craft more targeted attacks, bypass authentication mechanisms, or identify additional vulnerabilities within the same system. The exposure of partition names reveals the logical separation of network resources, potentially enabling attackers to map out the organization's network topology and identify high-value targets. Additionally, agent names can provide insights into the specific authentication protocols and security controls in place, making it easier for threat actors to develop tailored attack vectors. This vulnerability directly aligns with ATT&CK technique T1082 Discovery - System Information Discovery, where adversaries gather information about the system and network environment to plan further operations.
Organizations affected by this vulnerability should implement immediate mitigation strategies to protect their network access control infrastructure. The primary recommendation involves applying the official F5 security patches released to address this specific information disclosure flaw, which typically include enhanced URI parameter sanitization and filtering mechanisms. Network administrators should also consider implementing web application firewalls or security monitoring solutions that can detect and block suspicious URI patterns containing configuration information. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities within the BIG-IP environment, as this flaw demonstrates the importance of proper input validation and parameter handling in web-based security systems. The vulnerability highlights the critical need for comprehensive security testing of web interfaces and the implementation of defense-in-depth strategies that prevent information leakage even when other security controls fail. Organizations should also review their access control policies and ensure that sensitive configuration information is not exposed through any web-based interfaces or URI parameters.