Cybersecurity Vulnerabilities

Critical Stack Overflow Vulnerability in Suricata: CVE-2025-64333 Demands Immediate Attention

Overview

A high-severity vulnerability, identified as CVE-2025-64333, has been discovered in Suricata, a widely used network intrusion detection system (IDS), intrusion prevention system (IPS), and network security monitoring (NSM) engine. This vulnerability, if exploited, can lead to a stack overflow and cause Suricata to crash, potentially disrupting network security operations. The issue stems from the processing of excessively large HTTP content types during logging. Patches are available to address this vulnerability.

Technical Details

The vulnerability resides in how Suricata handles large HTTP content types when logging network traffic. Specifically, an overly large content type processed during HTTP stream reassembly and subsequent logging can exhaust the stack space, leading to a stack overflow. This overflow results in the Suricata process crashing. The vulnerability affects Suricata versions prior to 7.0.13 and 8.0.2.

CVSS Analysis

The Common Vulnerability Scoring System (CVSS) has assigned a score of 7.5 to CVE-2025-64333, indicating a HIGH severity. This score reflects the potential for significant disruption due to a denial-of-service (DoS) condition caused by the Suricata crash.

Possible Impact

Successful exploitation of CVE-2025-64333 can have several critical impacts:

  • Denial of Service (DoS): The most immediate impact is a crash of the Suricata process, rendering it unable to monitor network traffic.
  • Security Monitoring Blind Spot: A crashed Suricata instance leaves a blind spot in network security monitoring, potentially allowing malicious traffic to go undetected.
  • Evasion of Security Controls: Attackers might leverage this vulnerability to evade Suricata’s security controls, especially during attacks involving large HTTP payloads.

Mitigation or Patch Steps

To address this vulnerability, the following steps are recommended:

  • Upgrade Suricata: The primary mitigation is to upgrade to Suricata versions 7.0.13 or 8.0.2, which contain the necessary patches.
  • Workaround (if immediate patching is not possible): Limit the stream.reassembly.depth configuration option to less than half of the stack size. However, note that reducing this value may impact stream reassembly performance and accuracy.
  • Increase Stack Size (Advanced): While not a complete solution, increasing the process stack size can make it less likely that the bug will trigger, but it’s still recommended to patch.

Important: Prioritize upgrading to the patched versions of Suricata for the most effective and reliable mitigation.

References

Cybersecurity specialist and founder of Gowri Shankar Infosec - a professional blog dedicated to sharing actionable insights on cybersecurity, data protection, server administration, and compliance frameworks including SOC 2, PCI DSS, and GDPR.

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