CVE-2023-43746 in BIG-IP
Summary
by MITRE • 10/25/2023
When running in Appliance mode, an authenticated user assigned the Administrator role may be able to bypass Appliance mode restrictions, utilizing BIG-IP external monitor on a BIG-IP system. A successful exploit can allow the attacker to cross a security boundary. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
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Analysis
by VulDB Data Team • 10/28/2023
This vulnerability exists within F5 BIG-IP systems operating in Appliance mode where an authenticated user holding the Administrator role can potentially bypass security restrictions through improper handling of external monitors. The flaw specifically relates to how the system processes external monitor configurations, allowing privilege escalation and unauthorized access to restricted system functions. The vulnerability represents a critical security boundary violation that undermines the intended isolation mechanisms of Appliance mode deployments.
The technical implementation involves the manipulation of external monitor configurations within the BIG-IP management interface, where the system fails to properly validate access controls when processing these monitor objects. This weakness stems from inadequate input validation and privilege checking mechanisms that should prevent administrative users from accessing restricted system components. The vulnerability is categorized under CWE-284: Improper Access Control, which specifically addresses insufficient privileges or access control mechanisms that allow unauthorized access to resources. When exploited, the attacker can effectively circumvent the security boundaries that normally isolate administrative functions from regular operational tasks.
The operational impact of this vulnerability extends beyond simple privilege escalation to include potential system compromise and unauthorized access to sensitive network infrastructure components. An attacker exploiting this vulnerability could gain access to system configuration data, network monitoring information, and potentially manipulate network traffic handling through the external monitor functionality. This represents a significant risk to organizations relying on BIG-IP systems for application delivery and network security, as it allows for unauthorized access to critical infrastructure components. The attack vector requires authentication as an administrator but does not require additional privileges or complex exploitation techniques, making it particularly dangerous in environments where administrative accounts may be compromised.
Organizations should immediately implement mitigations including restricting access to external monitor configuration interfaces, enforcing strict administrative access controls, and monitoring for unauthorized configuration changes. The recommended approach involves implementing role-based access controls that prevent administrative users from modifying external monitor objects, while also ensuring that all administrative accounts are protected through multi-factor authentication. Security teams should also review existing external monitor configurations and validate that proper access controls are in place to prevent unauthorized modifications. This vulnerability aligns with ATT&CK technique T1078.004: Valid Accounts, specifically focusing on the abuse of administrative privileges within network infrastructure systems. The mitigation strategies should also include regular security assessments and monitoring for anomalous administrative activities that might indicate exploitation attempts. Organizations should also verify that their BIG-IP systems are running supported software versions, as this vulnerability does not affect systems past their End of Technical Support lifecycle, ensuring proper vendor support and security updates are available.