CVE-2021-21828 : Security Advisory and Response
Learn about CVE-2021-21828, a heap-based buffer overflow vulnerability in AT&T Labs Xmill 0.7 that allows attackers to execute malicious files, with a high impact severity rating.
A heap-based buffer overflow vulnerability exists in the XML Decompression DecodeTreeBlock functionality of AT&T Labs Xmill 0.7, potentially allowing an attacker to trigger this vulnerability by providing a malicious file.
Understanding CVE-2021-21828
This section will provide insights into the nature and impact of the CVE-2021-21828 vulnerability.
What is CVE-2021-21828?
The CVE-2021-21828 is a heap-based buffer overflow vulnerability found in the XML Decompression DecodeTreeBlock functionality of AT&T Labs Xmill 0.7. The vulnerability arises due to the creation of a label in the default case of DecodeTreeBlock, which can be exploited by an attacker.
The Impact of CVE-2021-21828
The impact of this vulnerability is rated as 'High', with a base severity score of 8.1 according to the CVSS v3.0 metrics. The vulnerability can lead to confidentiality, integrity, and availability impacts on affected systems.
Technical Details of CVE-2021-21828
This section will delve into the technical aspects of the CVE-2021-21828 vulnerability.
Vulnerability Description
The vulnerability results from a heap-based buffer overflow in the XML Decompression DecodeTreeBlock function. It allows an attacker to exploit the creation of a label via CurPath::AddLabel in DecodeTreeBlock, leading to potential malicious file execution.
Affected Systems and Versions
The vulnerability affects AT&T Labs Xmill 0.7 and possibly Schneider Electric EcoStruxure Control Expert 15 versions.
Exploitation Mechanism
An attacker can exploit this vulnerability by providing a specially crafted malicious file to trigger the heap-based buffer overflow in the XML Decompression DecodeTreeBlock function.
Mitigation and Prevention
This section outlines the measures to mitigate and prevent exploitation of CVE-2021-21828.
Immediate Steps to Take
Affected users are advised to apply security patches provided by the vendor promptly. It is also recommended to restrict network access to vulnerable systems.
Long-Term Security Practices
Implementing secure coding practices, regular security audits, and maintaining up-to-date antivirus definitions can help prevent similar vulnerabilities in the future.
Patching and Updates
Ensure that affected systems are updated with the latest patches and security updates to address the vulnerability and enhance overall system security.