CVE-2019-6657 in BIG-IP
Summary
by MITRE
On BIG-IP 13.1.0-13.1.3.1, 12.1.0-12.1.5, and 11.5.2-11.6.5.1, a reflected cross-site scripting (XSS) vulnerability exists in an undisclosed page of the BIG-IP Traffic Management User Interface (TMUI), also known as the BIG-IP Configuration utility.
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Analysis
by VulDB Data Team • 02/01/2024
The vulnerability identified as CVE-2019-6657 represents a critical reflected cross-site scripting flaw within F5 Networks BIG-IP Traffic Management User Interface, affecting multiple versions including 13.1.0 through 13.1.3.1, 12.1.0 through 12.1.5, and 11.5.2 through 11.6.5.1. This vulnerability resides in an undisclosed page of the BIG-IP Configuration utility, which serves as the primary administrative interface for managing F5 load balancers and application delivery controllers. The TMUI interface is a web-based administrative console that allows network administrators to configure and monitor BIG-IP systems, making it a prime target for attackers seeking to compromise network infrastructure. The reflected XSS vulnerability specifically allows malicious actors to inject malicious scripts into the web interface through crafted URLs or parameters that are then reflected back to users, potentially executing unauthorized code in the context of the victim's browser session.
This vulnerability stems from inadequate input validation and output encoding within the affected BIG-IP TMUI components. The flaw occurs when user-supplied input is not properly sanitized before being rendered in web responses, creating an environment where attacker-controlled data can be interpreted as executable JavaScript code. The issue manifests in the way the system handles HTTP requests and responses within the configuration utility, particularly when processing parameters that should be strictly validated and escaped. According to CWE classification, this vulnerability maps to CWE-79 which specifically addresses Cross-site Scripting flaws, and more specifically to CWE-74 where improper neutralization of special elements in output used by a downstream component can lead to XSS attacks. The vulnerability's impact is amplified by the privileged nature of the TMUI interface, as successful exploitation could allow attackers to gain administrative access to critical network infrastructure components.
The operational impact of CVE-2019-6657 extends beyond simple script execution, as it provides attackers with potential access to sensitive network configurations, user credentials, and system management functions. Network administrators who interact with the BIG-IP TMUI interface become potential victims of this vulnerability, as the reflected nature of the attack means that simply clicking a malicious link or visiting a compromised page could result in unauthorized code execution. This vulnerability directly aligns with ATT&CK technique T1059.007 which covers Scripting and T1078.004 which addresses Valid Accounts, as attackers could leverage this vulnerability to establish persistent access to network infrastructure. The potential for privilege escalation exists when attackers can manipulate the administrative interface, potentially leading to complete compromise of the BIG-IP system and all services it manages. Organizations running affected BIG-IP versions face significant risk of data breaches, service disruption, and unauthorized network access, particularly in environments where these systems are directly exposed to untrusted networks.
Mitigation strategies for CVE-2019-6657 require immediate implementation of multiple defensive measures to protect against exploitation. Organizations should prioritize applying the official F5 security patches released in response to this vulnerability, which address the input validation issues within the TMUI interface. Network segmentation and access controls should be implemented to restrict direct access to the BIG-IP TMUI interface from untrusted networks, ensuring that only authorized personnel can reach the administrative console. Implementing web application firewalls and content security policies can help detect and prevent malicious requests targeting the vulnerable interface components. Additionally, organizations should conduct comprehensive network monitoring to detect suspicious activities related to the TMUI interface, including unusual access patterns or attempts to access the vulnerable pages. Security awareness training for administrators is crucial to prevent social engineering attacks that might attempt to lure users into clicking malicious links that exploit this vulnerability. The remediation process should include thorough vulnerability scanning of all BIG-IP systems to identify any remaining instances of the affected versions, as well as implementation of proper logging and alerting mechanisms to detect potential exploitation attempts.