CVE-2021-26733 : Security Advisory and Response

A broken access control vulnerability in the FirstReset_handler_func function of spx_restservice allows an attacker to arbitrarily send reboot commands to the BMC, causing a Denial-of-Service (DoS) condition. This vulnerability affects Lanner Inc IAC-AST2500A standard firmware version 1.10.0.

Understanding CVE-2021-26733

This section provides details about the impact, technical aspects, and mitigation strategies related to CVE-2021-26733.

What is CVE-2021-26733?

CVE-2021-26733 is a broken access control vulnerability in the spx_restservice that allows unauthorized reboot commands, leading to a denial-of-service scenario.

The Impact of CVE-2021-26733

The vulnerability enables attackers to disrupt the availability of the BMC by sending rogue reboot commands, potentially causing operational downtime.

Technical Details of CVE-2021-26733

Below are the detailed technical aspects of CVE-2021-26733, including the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability stems from the improper access control implementation in the FirstReset_handler_func function, allowing unauthenticated users to trigger reboot commands.

Affected Systems and Versions

Lanner Inc IAC-AST2500A standard firmware version 1.10.0 is confirmed to be impacted by this vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability by sending malicious requests to the targeted BMC, leveraging the broken access control in the affected function.

Mitigation and Prevention

To address CVE-2021-26733, immediate actions and long-term security practices need to be implemented to safeguard systems.

Immediate Steps to Take

Implement access controls, update firmware to patched versions, and monitor BMC activity to detect anomalous behavior promptly.

Long-Term Security Practices

Establish a robust security posture by regularly applying security updates, conducting security assessments, and educating personnel on secure practices.

Patching and Updates

Ensure timely application of vendor-supplied patches and firmware updates to mitigate the vulnerability effectively.