CVE-2023-20821 Explained : Impact and Mitigation

This is a detailed overview of CVE-2023-20821, a vulnerability identified and published by MediaTek, impacting various MediaTek products.

Understanding CVE-2023-20821

CVE-2023-20821 is a security vulnerability found in nvram that could potentially lead to an out-of-bounds write due to a missing bounds check. This flaw could be exploited by threat actors to achieve local escalation of privilege without requiring user interaction. The patch ID for this vulnerability is ALPS07937113, with the Issue ID also being ALPS07937113.

What is CVE-2023-20821?

The vulnerability in nvram could allow malicious actors to carry out an out-of-bounds write operation, potentially leading to the local escalation of privileges on the affected systems. The exploit does not require any user interaction, making it particularly dangerous.

The Impact of CVE-2023-20821

The impact of CVE-2023-20821 is significant as it could allow threat actors to gain elevated privileges on the affected systems, posing a serious risk to the overall security posture.

Technical Details of CVE-2023-20821

The technical details of CVE-2023-20821 include:

Vulnerability Description

The vulnerability arises due to a missing bounds check in nvram, which could be exploited to perform out-of-bounds writes, leading to potential privilege escalation.

Affected Systems and Versions

Several MediaTek products are affected by this vulnerability, including MT2713, MT2735, MT6833, MT6835, MT6853, and numerous others. The impacted versions include Android 11.0, 12.0, 13.0, OpenWrt 1907, 2102, Yocto 2.6, and other related versions.

Exploitation Mechanism

The exploitation of CVE-2023-20821 does not require any user interaction, making it a critical risk for devices running the affected versions.

Mitigation and Prevention

To address CVE-2023-20821, it is crucial to take immediate steps and implement long-term security practices to mitigate the risk effectively.

Immediate Steps to Take

Organizations and users should apply the provided patch ID ALPS07937113 to address the vulnerability promptly.
Monitor for any unauthorized system access or unusual activities that may indicate exploitation of the vulnerability.

Long-Term Security Practices

Regularly update and patch systems to prevent vulnerabilities.
Conduct security assessments and audits to identify and address potential weaknesses in the system.

Patching and Updates

Stay informed about security updates from MediaTek and apply patches and fixes as soon as they are available to ensure the security of the systems against known vulnerabilities.