CVE-2024-32663 in Suricata
Summary
by MITRE • 05/07/2024
Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.5 and 6.0.19, a small amount of HTTP/2 traffic can lead to Suricata using a large amount of memory. The issue has been addressed in Suricata 7.0.5 and 6.0.19. Workarounds include disabling the HTTP/2 parser and reducing `app-layer.protocols.http2.max-table-size` value (default is 65536).
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Analysis
by VulDB Data Team • 04/01/2025
The vulnerability identified as CVE-2024-32663 affects Suricata, a widely deployed network intrusion detection system that functions as both an intrusion prevention system and network security monitoring engine. This issue represents a memory exhaustion vulnerability that specifically targets the HTTP/2 protocol handling capabilities within Suricata's application layer parsing mechanisms. The flaw manifests when processing certain patterns of HTTP/2 traffic that trigger excessive memory consumption within the system's parser components.
The technical root cause of this vulnerability lies in the improper handling of HTTP/2 protocol data structures within Suricata's application layer processing framework. When Suricata encounters specific combinations of HTTP/2 frames and headers, particularly those involving header table management and compression algorithms, the system's memory allocation patterns become inefficient and potentially unbounded. This behavior is classified under CWE-400 as an unspecified vulnerability related to resource exhaustion, specifically memory consumption. The vulnerability demonstrates characteristics of a denial of service condition where legitimate network traffic can be exploited to consume excessive system resources, ultimately leading to system instability or complete service disruption.
The operational impact of this vulnerability extends beyond simple performance degradation to potentially compromise the entire network monitoring infrastructure. Organizations relying on Suricata for network security monitoring face significant risks when this vulnerability is exploited, as the excessive memory usage can cause the system to become unresponsive or crash entirely. This creates a window of opportunity for attackers to bypass network security controls while the system is recovering from the memory exhaustion event. The vulnerability affects both the 6.0.x and 7.0.x release series, indicating a fundamental flaw in the HTTP/2 parsing implementation that spans multiple versions of the software. The issue particularly impacts environments where HTTP/2 traffic is prevalent, such as modern web applications, cloud services, and enterprise networks with significant HTTPS traffic.
The remediation approach for this vulnerability involves upgrading to Suricata versions 7.0.5 or 6.0.19, which contain patches addressing the memory allocation issues in the HTTP/2 parser. Organizations can also implement temporary workarounds to mitigate the risk while planning upgrades, including disabling the HTTP/2 parser entirely or reducing the maximum table size parameter from its default value of 65536 bytes. These mitigation strategies align with ATT&CK technique T1499.004, which involves resource exhaustion attacks, and represent defensive measures that can be applied to reduce the attack surface. The vulnerability's classification as a memory exhaustion issue makes it particularly relevant to cybersecurity frameworks that emphasize system resilience and resource management. Organizations should also consider implementing network segmentation and monitoring to detect unusual memory consumption patterns that might indicate exploitation attempts, while maintaining regular patch management processes to ensure all network security appliances remain protected against similar vulnerabilities.