CVE-2025-62792: Wazuh Buffer Overflow Vulnerability

CVE-2025-62792 Overview

CVE-2025-62792 is an Out-of-Bounds Read vulnerability affecting Wazuh, a free and open source platform used for threat prevention, detection, and response. Prior to version 4.12.0, a buffer over-read occurs in the w_expression_match() function when strlen() is called on str_test, because the corresponding buffer is not being properly NULL terminated during its allocation in OS_CleanMSG().

A compromised agent can cause a READ operation beyond the end of the allocated buffer by sending a specially crafted message to the Wazuh manager. This buffer may contain sensitive information, potentially allowing an attacker to access data beyond the intended memory boundaries.

Critical Impact

A compromised Wazuh agent can exploit this vulnerability to read sensitive data from the Wazuh manager's memory by sending specially crafted messages, potentially exposing confidential information stored in adjacent memory regions.

Affected Products

• Wazuh versions prior to 4.12.0
• Wazuh Manager component
• Systems using Wazuh agent-manager communication

Discovery Timeline

• 2025-10-29 - CVE-2025-62792 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2025-62792

Vulnerability Analysis

This vulnerability is classified as CWE-126 (Buffer Over-read), a type of memory safety issue where a program reads data past the end of an allocated buffer. The flaw exists in the message processing pipeline of the Wazuh manager, specifically in how incoming agent messages are sanitized and processed.

When the Wazuh manager receives a message from an agent, it processes the data through the OS_CleanMSG() function. During buffer allocation in this function, the resulting buffer is not properly NULL terminated. Subsequently, when w_expression_match() calls strlen() on str_test, it continues reading memory beyond the intended buffer boundaries until it encounters a NULL byte, potentially exposing sensitive information stored in adjacent memory.

The vulnerability can be exploited remotely over the network without requiring authentication. An attacker who has compromised a Wazuh agent or can craft messages that appear to originate from an agent can send specially formatted messages to trigger this condition.

Root Cause

The root cause of this vulnerability lies in improper buffer termination during memory allocation in the OS_CleanMSG() function. When a buffer is allocated to hold the cleaned message content, the function fails to ensure proper NULL termination. This oversight means that string operations like strlen() will read beyond the allocated buffer space, as C string functions rely on NULL terminators to determine string boundaries.

This represents a classic memory safety issue where the programmer assumed the buffer would be properly terminated but did not explicitly enforce this invariant in the code path.

Attack Vector

The attack vector for CVE-2025-62792 involves network-based exploitation through the Wazuh agent-to-manager communication channel. An attacker must be able to send specially crafted messages to the Wazuh manager, which typically requires:

1. Compromising an existing Wazuh agent that has established communication with the target manager
2. Crafting a malicious message that triggers the buffer over-read condition in OS_CleanMSG()
3. The over-read operation then exposes data from memory regions adjacent to the allocated buffer

The vulnerability does not require user interaction and can be exploited without authentication if the attacker has access to the agent communication channel. While the direct impact is limited to information disclosure rather than code execution, the exposed memory contents could contain sensitive operational data, credentials, or other confidential information processed by the Wazuh manager.

Detection Methods for CVE-2025-62792

Indicators of Compromise

• Anomalous or malformed messages received by the Wazuh manager from agent connections
• Unusual memory access patterns in the Wazuh manager process
• Agent messages with atypical formatting or unexpected content lengths
• Crash logs or error messages related to memory access violations in w_expression_match() or OS_CleanMSG()

Detection Strategies

• Monitor Wazuh manager logs for unusual agent communication patterns or parsing errors
• Implement network traffic analysis to detect malformed agent-to-manager messages
• Deploy memory protection tools to detect out-of-bounds read operations in the Wazuh manager process
• Use SentinelOne's runtime protection to identify and alert on memory safety violations

Monitoring Recommendations

• Enable detailed logging for Wazuh agent-manager communications
• Implement alerting for repeated connection attempts or message parsing failures
• Monitor system resources for signs of memory corruption or abnormal behavior
• Regularly audit the integrity and authentication of connected Wazuh agents

How to Mitigate CVE-2025-62792

Immediate Actions Required

• Upgrade Wazuh to version 4.12.0 or later immediately
• Audit all connected Wazuh agents for signs of compromise
• Review access controls on the Wazuh manager communication ports
• Implement network segmentation to limit exposure of the Wazuh manager to only trusted agents

Patch Information

This vulnerability is fixed in Wazuh version 4.12.0. The patch addresses the improper buffer termination in OS_CleanMSG() by ensuring all allocated buffers are properly NULL terminated before string operations are performed. Organizations should upgrade to version 4.12.0 or later as soon as possible.

For detailed patch information and upgrade instructions, refer to the GitHub Security Advisory.

Workarounds

• Restrict network access to the Wazuh manager to only trusted, verified agents
• Implement additional network-level monitoring between agents and the manager
• Consider deploying a Web Application Firewall (WAF) or similar filtering mechanism to inspect agent traffic
• Temporarily isolate any suspected compromised agents until the patch can be applied