CVE-2019-6595 in BIG-IP Access Policy Manager
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in F5 BIG-IP Access Policy Manager (APM) 11.5.x and 11.6.x Admin Web UI.
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Analysis
by VulDB Data Team • 07/19/2023
The CVE-2019-6595 vulnerability represents a critical cross-site scripting flaw within the F5 BIG-IP Access Policy Manager component affecting versions 11.5.x and 11.6.x of the administrative web interface. This vulnerability resides in the user authentication and access control mechanisms of the BIG-IP platform, which serves as a cornerstone for enterprise network security infrastructure. The flaw specifically impacts the administrative web UI where security policies are configured and managed, creating a potential attack vector that could be exploited by malicious actors to gain unauthorized access to sensitive network resources. The vulnerability's presence in the APM module is particularly concerning as this component controls access to enterprise applications and services, making it a prime target for cybercriminals seeking to compromise network perimeters.
The technical implementation of this XSS vulnerability stems from inadequate input validation and output encoding within the administrative web interface of the BIG-IP system. When administrators interact with the APM configuration pages, the system fails to properly sanitize user-supplied input before rendering it back to the browser. This allows attackers to inject malicious JavaScript code through crafted parameters or form fields within the web interface. The vulnerability manifests when the system processes user input without sufficient sanitization, leading to the execution of malicious scripts in the context of the victim's browser session. This type of flaw falls under the CWE-79 category of Cross-Site Scripting, specifically representing a stored XSS variant where malicious code can persist within the application's data storage and execute whenever the affected page is accessed. The vulnerability is particularly dangerous because it affects the administrative interface, meaning successful exploitation could provide attackers with elevated privileges and access to critical network infrastructure controls.
The operational impact of CVE-2019-6595 extends beyond simple script execution, as it fundamentally undermines the security posture of organizations relying on F5 BIG-IP systems for access control. Attackers who successfully exploit this vulnerability can perform actions such as stealing administrative session cookies, executing arbitrary commands within the context of the administrative interface, and potentially gaining access to the underlying network infrastructure. The attack surface is significant since the administrative web UI is frequently accessed by security personnel who possess elevated privileges and system access. This vulnerability enables attackers to bypass traditional security controls and directly compromise the access management layer that protects enterprise applications and services. The potential for privilege escalation and persistent access makes this vulnerability particularly attractive to advanced persistent threat actors and increases the risk of data breaches and unauthorized network access. The impact is further amplified by the fact that many organizations may not regularly update their BIG-IP systems, leaving them vulnerable to exploitation for extended periods.
Organizations affected by CVE-2019-6595 should implement immediate mitigation strategies while planning for long-term remediation through official F5 patches and updates. The primary defense mechanism involves applying the vendor-supplied security patches released by F5, which address the input validation and output encoding deficiencies within the APM administrative interface. Network segmentation and monitoring of administrative access attempts should be enhanced to detect potential exploitation attempts, as the vulnerability requires interaction with the administrative web interface. Implementing web application firewalls and content security policies can provide additional layers of protection against XSS attacks targeting the affected components. Security teams should also conduct thorough vulnerability assessments to identify any other potentially affected components within their F5 BIG-IP deployments, as similar vulnerabilities may exist in other modules. The ATT&CK framework categorizes this type of vulnerability under the T1059.007 technique for command and scripting interpreter, as exploitation involves the execution of malicious scripts within the target environment. Organizations should also review their incident response procedures to ensure readiness for potential exploitation attempts, as the vulnerability could be leveraged for initial access or lateral movement within compromised networks. Regular security awareness training for administrators is essential to prevent social engineering attacks that might complement this technical vulnerability.