A new vulnerability identified as CVE-2024-36468 has been discovered in Zabbix, a widely used open-source monitoring tool for networks and applications. This vulnerability is a stack buffer overflow that occurs in the zbx_snmp_cache_handle_engineid function within the Zabbix server/proxy code. This vulnerability can result in a significant impact on the security and integrity of the affected Zabbix server.

In this post, we will provide a detailed analysis of the vulnerability, its exploit details, relevant code snippets, and original references. The aim is to provide a comprehensive understanding of CVE-2024-36468 and its implications.

Vulnerability Description

The CVE-2024-36468 vulnerability stems from the improper handling of data copying from session->securityEngineID to local_record.engineid within the zbx_snmp_cache_handle_engineid function. There is no proper bounds checking during this process, which results in a stack buffer overflow.

Here's a relevant code snippet, demonstrating the issue

int zbx_snmp_cache_handle_engineid(struct snmp_session *session)
{
    zbx_snmp_engineid_record_t local_record;

    ...

    memcpy(local_record.engineid, session->securityEngineID, session->securityEngineIDLen);

    ...
}

In the above code snippet, the memcpy function is used to copy data from session->securityEngineID to local_record.engineid without ensuring that the size of the data being copied is within the bounds of the destination buffer.

Exploit Details

A potential attacker could exploit this vulnerability by sending a carefully crafted SNMPv3 request with a long "engineID" value to the vulnerable Zabbix server or proxy. By doing so, they could trigger the stack buffer overflow which may lead to the execution of arbitrary code or cause a denial-of-service condition on the target system.

Due to this vulnerability's potential for significant impact, it is vital to apply necessary security updates and patches as they become available.

Original References

This vulnerability was initially reported to and patched by the Zabbix project. You can find more details on the issue and patch in the following resources:
- ZABBIX GitHub Repository: Patch Commit
- Zabbix Technical Blog: Vulnerabilityannouncement and details by the Zabbix team

1. Update your Zabbix server and proxy to the latest version, which includes the necessary patch to fix the vulnerability.
2. Limit access to the SNMPv3 functionality on the Zabbix server and proxy by restricting access via network policies, firewalls, and other security measures.

Conclusion

The CVE-2024-36468 stack buffer overflow vulnerability in the Zabbix server/proxy is a serious security issue that requires immediate attention and remediation. By understanding the details of the vulnerability, its exploit potential, and available mitigations, organizations running Zabbix can effectively secure their systems and protect against potential attacks. As always, it is essential to stay informed about emerging vulnerabilities and apply necessary security patches and updates in a timely manner.

Timeline

Published on: 11/27/2024 12:15:20 UTC