CVE-2025-64333 is a stack-based buffer overflow vulnerability identified in the Suricata network intrusion detection and prevention system, developed by the Open Information Security Foundation (OISF). Suricata versions prior to 7.0.13 and 8.0.2 are affected. The vulnerability arises when Suricata processes and logs HTTP traffic with a large content type header. Specifically, the handling of this large HTTP content type causes a stack overflow condition, which leads to a crash of the Suricata process. This crash results in a denial of service (DoS) condition, impacting the availability of the network security monitoring system. The vulnerability is classified under CWE-121 (stack-based buffer overflow). The CVSS v3.1 base score is 7.5, indicating high severity, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no impact on confidentiality or integrity (C:N/I:N), but high impact on availability (A:H). No known exploits are currently reported in the wild. Mitigation includes upgrading Suricata to versions 7.0.13 or 8.0.2 and above. As a temporary workaround, administrators can limit the stream.reassembly.depth configuration parameter to less than half the process stack size or increase the process stack size to reduce the likelihood of triggering the overflow. This vulnerability primarily affects the availability of Suricata-based monitoring systems, which could lead to blind spots in network defense if exploited.

For European organizations, the primary impact of CVE-2025-64333 is the potential denial of service of Suricata-based network intrusion detection and prevention systems. Suricata is widely used in enterprise, government, and critical infrastructure sectors for network security monitoring. A crash caused by this vulnerability could result in loss of visibility into network traffic, delayed detection of malicious activity, and increased risk of undetected attacks. This is particularly critical for sectors such as finance, energy, telecommunications, and public administration, where continuous monitoring is essential for operational security and compliance with regulations like NIS2 and GDPR. The lack of confidentiality or integrity impact means data breaches are unlikely directly from this flaw, but the availability impact can indirectly facilitate attacks by disabling defenses. Organizations relying on Suricata for real-time threat detection may experience operational disruptions and increased exposure to cyber threats if the vulnerability is exploited. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits targeting this flaw.

1. Immediate upgrade of Suricata installations to version 7.0.13 or 8.0.2 or later to apply the official patch addressing the buffer overflow. 2. As a temporary measure before patching, configure the stream.reassembly.depth parameter to a value less than half the process stack size to reduce the chance of triggering the overflow. 3. Increase the process stack size where possible to make exploitation less likely. 4. Implement network traffic filtering to limit or scrutinize unusually large HTTP content type headers that could trigger the vulnerability. 5. Monitor Suricata logs and system stability for signs of crashes or abnormal behavior indicative of attempted exploitation. 6. Incorporate this vulnerability into vulnerability management and incident response plans to ensure rapid detection and remediation. 7. Conduct regular security audits and penetration testing focusing on IDS/IPS resilience. 8. Educate network security teams about this vulnerability and the importance of timely patching and configuration management.