CVE-2021-42252 : Vulnerability Insights and Analysis

An issue was discovered in aspeed_lpc_ctrl_mmap in drivers/soc/aspeed/aspeed-lpc-ctrl.c in the Linux kernel before 5.14.6. Local attackers able to access the Aspeed LPC control interface could overwrite memory in the kernel and potentially execute privileges, aka CID-b49a0e69a7b1. This occurs because a certain comparison uses values that are not memory sizes.

Understanding CVE-2021-42252

This CVE involves a vulnerability in the Linux kernel that could allow attackers to overwrite kernel memory and potentially execute privileged actions.

What is CVE-2021-42252?

The CVE-2021-42252 vulnerability is caused by a flaw in aspeed_lpc_ctrl_mmap in the Linux kernel, affecting versions prior to 5.14.6. Unauthorized local users with access to the Aspeed LPC control interface can exploit this issue.

The Impact of CVE-2021-42252

The vulnerability could lead to memory corruption within the kernel, enabling attackers to potentially execute arbitrary code with elevated privileges.

Technical Details of CVE-2021-42252

This section dives deeper into the technical aspects of the CVE.

Vulnerability Description

The vulnerability arises from improper comparisons in the aspeed_lpc_ctrl_mmap function in the Linux kernel, allowing attackers to manipulate memory content improperly.

Affected Systems and Versions

The issue impacts Linux kernel versions before 5.14.6.

Exploitation Mechanism

Unauthorized local attackers exploiting the Aspeed LPC control interface can leverage the vulnerability to overwrite crucial kernel memory.

Mitigation and Prevention

Protective measures to address and prevent the exploitation of CVE-2021-42252.

Immediate Steps to Take

Update the Linux kernel to version 5.14.6 or newer.
Restrict access to the Aspeed LPC control interface to authorized personnel only.
Monitor system logs for any unauthorized memory modification attempts.

Long-Term Security Practices

Regularly audit and review kernel code for vulnerabilities.
Implement proper privilege separation to mitigate the impact of potential exploits.

Patching and Updates

Apply security patches promptly to ensure system protection against known vulnerabilities.