CVE-2025-64330: Critical Heap Overflow Vulnerability Threatens Suricata Security

Published: 2025-11-26T23:15:48.093

Overview

This article details CVE-2025-64330, a high-severity vulnerability affecting Suricata, a leading open-source network intrusion detection system (IDS), intrusion prevention system (IPS), and network security monitoring (NSM) engine. This heap overflow vulnerability, if exploited, can lead to crashes and potentially arbitrary code execution. It’s crucial to understand the nature of this flaw and take immediate action to mitigate the risk.

Technical Details

CVE-2025-64330 involves a single-byte read heap overflow within Suricata’s logging functionality. Specifically, the vulnerability occurs when logging the verdict (alert or drop) in eve.alert and eve.drop records. This happens under specific conditions: the per-packet alert queue must be filled with alerts, followed by a pass rule. This scenario triggers an out-of-bounds read, leading to a crash.

The vulnerability is triggered by a malformed packet stream designed to rapidly fill the alert queue and then trigger a pass, exploiting a boundary condition in the verdict logging process.

CVSS Analysis

The Common Vulnerability Scoring System (CVSS) assigns CVE-2025-64330 a score of 7.5, indicating a HIGH severity. This score reflects the potential for significant impact and the relative ease with which the vulnerability can be exploited.

Possible Impact

A successful exploit of CVE-2025-64330 can lead to the following:

• Denial of Service (DoS): The most likely outcome is a crash of the Suricata process, effectively disabling network security monitoring and protection.
• Potential for Arbitrary Code Execution: While less likely, in some configurations or environments, a heap overflow can potentially be leveraged to execute arbitrary code, leading to a full system compromise.

Mitigation and Patch Steps

The Open Information Security Foundation (OISF) has addressed this vulnerability in the following Suricata releases:

• Suricata 7.0.13
• Suricata 8.0.2

Immediate action is required:

1. Upgrade Suricata: Upgrade your Suricata installation to version 7.0.13 or 8.0.2 or later. Follow the official Suricata upgrade instructions for your specific platform.
2. Increase Alert Queue Size (Workaround): If an immediate upgrade is not possible, a temporary workaround involves increasing the alert queue size in the suricata.yaml configuration file. Locate the packet-alert-max setting and increase its value. This reduces the likelihood of the queue being filled, mitigating the vulnerability. Note: This is not a substitute for patching!

Here’s an example of how to adjust the packet-alert-max in suricata.yaml:

    packet-alert-max: 8192  # Increase from the default value
    

References

• Suricata Commit 482e5eac9218d007adbe2410d6c00173368ce947
• OISF Security Advisory GHSA-83v7-gm34-f437