Wazuh is a free and open source platform used for threat prevention, detection, and response. This vulnerability allows a stack-based buffer overflow in print_hex_string() in wazuh-remoted, affecting versions from 4.8.0 to before 4.14.4. The issue arises when attacker-controlled bytes are formatted using sprintf, leading to out-of-bounds writes that can compromise the stack. Specifically, the bug occurs on platforms where a char is treated as signed, allowing the formatting of certain input bytes to exceed the allocated buffer size.
The vulnerable path is reachable remotely via TCP/1514, prior to any agent authentication or registration logic. An oversized length prefix can trigger the ‘unexpected message (hex)’ diagnostic path, leading to not only the buffer overflow but also to log amplification. This means that for each trigger, an attacker-controlled hex dump is logged, which can degrade monitoring fidelity and consume significant disk I/O resources.
This issue has been patched in version 4.14.4. Organizations running affected versions should prioritize updating to mitigate potential risks associated with this vulnerability.
Risk to organizations includes exposure to remote exploitation, which can lead to unauthorized access and potential data integrity issues. Given the nature of the vulnerability, organizations should address it in priority patch cycle.
The CVSS score for this vulnerability is 6.5, indicating a medium severity level. However, the potential for exploitation, coupled with the availability of attack vectors, necessitates immediate attention.
Vulnerability Details
The CVE-2026-28221 vulnerability is classified under CWE-121 and CWE-400. The vulnerability is characterized by the following traits:
Attribute | Detail |
|---|---|
CVSS Score | 6.5 |
Severity Level | Medium |
Attack Vector | Network |
Attack Complexity | Low |
Privileges Required | None |
User Interaction | None |
Scope | Unchanged |
Risk & Impact Analysis
The risk to organizations includes exposure to unauthorized access and potential data integrity issues. The attack vector is network-based, allowing for exploitation without the need for user interaction or prior authentication. Given that the CVSS score is 6.5, organizations should schedule remediation for this vulnerability.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All Wazuh versions from 4.8.0 to before 4.14.4 are affected by this vulnerability. Organizations should verify their version and take action accordingly.
Mitigation & Remediation
Organizations should prioritize upgrading to Wazuh version 4.14.4 or later to mitigate this vulnerability. Additionally, applying configuration hardening practices and network controls can help reduce the risk of exploitation. For further guidance, consider engaging in penetration testing to identify potential weaknesses in your deployment.
Detection Guidance
Organizations should monitor logs for unusual patterns, particularly related to oversized messages being processed by Wazuh. Regular log reviews can help identify any unauthorized access attempts or unexpected log contents.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability highlights the importance of secure coding practices and regular updates to open-source components. It represents a common flaw where data handled by external inputs can lead to severe consequences. Security teams should learn from this incident to enhance their defensive strategies.
To stay informed on the latest vulnerabilities and trends, organizations are encouraged to follow best practices in penetration testing methodology and implement a robust vulnerability management program to proactively address potential risks.
Finally, consider reviewing strategies to enhance your API security as part of an overall defense-in-depth approach.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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