CVE-2019-6598 in BIG-IP
Summary
by MITRE
In BIG-IP 14.0.0-14.0.0.2, 13.0.0-13.1.0.7, 12.1.0-12.1.3.5, 11.6.1-11.6.3.2, or 11.5.1-11.5.8 or Enterprise Manager 3.1.1, malformed requests to the Traffic Management User Interface (TMUI), also referred to as the BIG-IP Configuration utility, may lead to disruption of TMUI services. This attack requires an authenticated user with any role (other than the No Access role). The No Access user role cannot login and does not have the access level to perform the attack.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 08/01/2023
The vulnerability identified as CVE-2019-6598 represents a significant security flaw within F5 Networks BIG-IP systems that affects multiple version ranges including 14.0.0 through 14.0.0.2, 13.0.0 through 13.1.0.7, 12.1.0 through 12.1.3.5, 11.6.1 through 11.6.3.2, and 11.5.1 through 11.5.8, along with Enterprise Manager 3.1.1. This vulnerability specifically targets the Traffic Management User Interface TMUI component which serves as the primary configuration utility for BIG-IP systems. The flaw manifests when the system processes malformed requests sent to the TMUI, potentially causing service disruption and unauthorized access to critical system functions. The vulnerability is categorized under CWE-20 as a weakness involving improper input validation, specifically related to insufficient validation of user-supplied data in web applications.
The technical implementation of this vulnerability exploits the authentication bypass mechanism within the TMUI interface where an authenticated user with any role other than the No Access role can craft specially malformed requests that trigger unexpected behavior in the system's request handling logic. This allows attackers to potentially disrupt TMUI services, which could lead to denial of service conditions and compromise the availability of critical network infrastructure management functions. The attack requires minimal privileges since any authenticated user can potentially exploit this weakness, making it particularly dangerous in environments where multiple users have varying levels of access to the system. The vulnerability does not require administrative privileges or root access to be exploited, which significantly broadens the attack surface and makes it more accessible to various threat actors.
The operational impact of CVE-2019-6598 extends beyond simple service disruption to potentially enable more sophisticated attacks that could compromise the integrity and availability of network infrastructure. Organizations relying on BIG-IP systems for load balancing, application delivery, and security services face significant risk from this vulnerability, as disruption of TMUI services could prevent administrators from managing critical network functions during security incidents. The attack vector involves sending malformed requests to the TMUI interface, which could cause the system to crash or become unresponsive, effectively denying access to legitimate users who need to perform configuration changes or monitor system status. This vulnerability directly impacts the availability of the BIG-IP system's management interface and could be leveraged as part of broader attack campaigns targeting enterprise network infrastructure.
Mitigation strategies for CVE-2019-6598 should include immediate implementation of F5's official security patches and updates that address the specific input validation issues within the TMUI component. Organizations should also implement network segmentation and access controls to limit exposure of the TMUI interface to only authorized personnel and systems. The principle of least privilege should be enforced by ensuring that users have the minimum necessary access rights to perform their functions, and that No Access role users remain properly configured to prevent unauthorized access attempts. Security monitoring should be enhanced to detect anomalous requests to the TMUI interface, and network administrators should consider implementing web application firewalls or intrusion detection systems that can identify and block malformed requests targeting the affected components. Additionally, regular security assessments and vulnerability scanning should be conducted to identify any potential exploitation attempts and ensure that all systems remain properly patched and configured according to industry best practices. This vulnerability aligns with ATT&CK techniques related to privilege escalation and denial of service, making it a critical concern for enterprise security teams managing F5 BIG-IP deployments.