CVE-2019-6624 in BIG-IP
Summary
by MITRE
On BIG-IP 14.1.0-14.1.0.5, 14.0.0-14.0.0.4, 13.0.0-13.1.1.4, and 12.1.0-12.1.4, an undisclosed traffic pattern sent to a BIG-IP UDP virtual server may lead to a denial-of-service (DoS).
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Analysis
by VulDB Data Team • 10/15/2023
The vulnerability identified as CVE-2019-6624 affects F5 BIG-IP network appliances running specific versions of the BIG-IP operating system including 14.1.0 through 14.1.0.5, 14.0.0 through 14.0.0.4, 13.0.0 through 13.1.1.4, and 12.1.0 through 12.1.4. This issue represents a significant security weakness that could be exploited to disrupt network services. The vulnerability specifically targets UDP virtual servers within the BIG-IP system architecture, making it particularly dangerous for organizations relying on these appliances for load balancing and traffic management. The flaw manifests when certain traffic patterns are sent to these UDP virtual servers, potentially causing complete service disruption.
The technical nature of this vulnerability stems from insufficient input validation and error handling within the BIG-IP system's UDP processing mechanisms. When malformed or specially crafted UDP packets are transmitted to the vulnerable virtual servers, the system fails to properly handle these traffic patterns, leading to system instability and eventual denial-of-service conditions. This behavior aligns with common software security weaknesses classified under CWE-20, which encompasses "Improper Input Validation" and CWE-121, which addresses "Stack-based Buffer Overflow" conditions that can occur when systems fail to properly validate network traffic inputs. The vulnerability represents a critical design flaw in how the BIG-IP system processes UDP traffic, particularly in its handling of edge cases and malformed packets.
The operational impact of CVE-2019-6624 extends far beyond simple service disruption, as it can affect critical network infrastructure that organizations depend upon for business continuity. Organizations utilizing F5 BIG-IP appliances for load balancing, application delivery, and traffic management face potential downtime that could span from minutes to hours depending on the severity of the attack and the organization's incident response capabilities. The vulnerability can be exploited remotely without authentication, making it particularly dangerous as attackers can target these systems from anywhere on the network. This characteristic places organizations at risk of both intentional attacks and accidental service degradation, with potential cascading effects on dependent services and applications that rely on the affected BIG-IP appliances for proper network function.
Mitigation strategies for CVE-2019-6624 should include immediate implementation of F5's official security patches and updates released to address this vulnerability. Organizations should also consider implementing network segmentation and access controls to limit exposure of vulnerable BIG-IP appliances to untrusted networks. Network monitoring solutions should be configured to detect unusual UDP traffic patterns that might indicate exploitation attempts, with intrusion detection systems capable of identifying and alerting on malformed UDP packets. Additionally, implementing rate limiting and connection tracking mechanisms on UDP virtual servers can help reduce the impact of potential DoS attacks. The vulnerability's classification under ATT&CK technique T1499.004, which covers "Endpoint Denial of Service," emphasizes the need for defensive measures that can detect and prevent such attacks, including the implementation of network-level protections and continuous monitoring of traffic patterns to identify anomalous behavior that could indicate exploitation attempts.