CVE-2025-64331 is a stack-based buffer overflow vulnerability identified in the Open Information Security Foundation's Suricata network IDS/IPS and NSM engine. Suricata versions prior to 7.0.13 and 8.0.2 are affected. The vulnerability arises when the HTTP response body limit is increased beyond default settings and the logging of printable HTTP bodies is enabled. Under these conditions, processing large HTTP file transfers can cause a stack overflow, leading to potential crashes or denial of service. This vulnerability is classified under CWE-121, indicating improper handling of buffer boundaries on the stack. The flaw does not require any privileges or user interaction to exploit, as it can be triggered remotely by sending specially crafted HTTP traffic that exceeds the configured limits. The impact is primarily on availability, as the overflow can cause Suricata to crash, disrupting network monitoring and intrusion detection capabilities. No confidentiality or integrity impacts are reported. The issue has been addressed in Suricata versions 7.0.13 and 8.0.2. As a workaround, users can revert to default HTTP response body limits and disable the logging of printable HTTP bodies, which is disabled by default. No known exploits have been observed in the wild to date, but the vulnerability's characteristics make it a significant risk for denial of service attacks against Suricata deployments.

For European organizations, this vulnerability poses a significant risk to network security monitoring and intrusion detection capabilities. Suricata is widely used in enterprise, government, and critical infrastructure sectors across Europe for real-time network traffic analysis. A successful exploitation could cause Suricata to crash, resulting in loss of visibility into network threats and potential blind spots for attackers. This is particularly critical for sectors such as finance, energy, telecommunications, and public administration, where continuous monitoring is essential for security and compliance. The denial of service impact could also disrupt incident response and forensic investigations. Since the vulnerability can be triggered remotely without authentication, attackers could exploit it from outside the network perimeter, increasing the threat surface. Although no data confidentiality or integrity loss is expected, the availability impact alone can have cascading effects on organizational security posture and operational continuity.

European organizations should prioritize upgrading Suricata to versions 7.0.13 or 8.0.2 or later, where the vulnerability is patched. Until upgrades can be applied, administrators should revert any increased HTTP response body limits back to default values and disable the logging of printable HTTP bodies, which is off by default. Network security teams should audit current Suricata configurations to identify if these settings have been modified. Implementing strict network segmentation and filtering to limit exposure of Suricata management interfaces and monitoring points can reduce attack surface. Continuous monitoring for Suricata process crashes or unusual HTTP traffic patterns indicative of exploitation attempts should be established. Additionally, integrating Suricata logs with SIEM solutions can help detect anomalies related to this vulnerability. Organizations should also maintain up-to-date incident response plans to quickly address potential denial of service incidents affecting network monitoring.