CVE-2021-28199 : Exploit Details and Defense Strategies

This article discusses the buffer overflow vulnerability in ASUS BMC's firmware, impacting multiple products, potentially allowing remote attackers to disrupt the Web service.

Understanding CVE-2021-28199

CVE-2021-28199 is a vulnerability in ASUS BMC's firmware Web management page, specifically in the Modify user's information function. The flaw arises from the lack of input validation for user-entered string lengths, leading to a buffer overflow scenario. Exploitation of this vulnerability could result in unauthorized termination of the Web service.

What is CVE-2021-28199?

The vulnerability in ASUS BMC's firmware allows remote attackers to cause a buffer overflow, taking advantage of the absence of proper string length validation in the Modify user's information function.

The Impact of CVE-2021-28199

The vulnerability presents a medium-severity risk, with a CVSS base score of 4.9. It requires high privileges to exploit and can result in a denial of service, affecting the availability of the service.

Technical Details of CVE-2021-28199

The vulnerability arises from a lack of string length validation in a specific function of ASUS BMC's firmware, potentially leading to a buffer overflow.

Vulnerability Description

The flaw allows remote attackers to trigger a buffer overflow by entering oversized strings in the Modify user's information function of ASUS BMC's firmware.

Affected Systems and Versions

Multiple products from ASUS are affected, including BMC firmware versions 1.09 to 1.15.6 across various server models.

Exploitation Mechanism

Remote attackers with high privileges can exploit the buffer overflow vulnerability to disrupt the Web service accessible via ASUS BMC's firmware.

Mitigation and Prevention

To address CVE-2021-28199, ASUS recommends updating the BMC firmware to the specified versions to mitigate the vulnerability.

Immediate Steps to Take

Update affected ASUS products' BMC firmware to the recommended versions to prevent exploitation of the buffer overflow vulnerability.

Long-Term Security Practices

Regularly monitor ASUS product security advisories for firmware updates and security patches to safeguard against potential vulnerabilities.

Patching and Updates

Ensure timely application of firmware updates and patches provided by ASUS to maintain the security integrity of BMC firmware across affected products.