CVE-2021-3753 : Security Advisory and Response

A race problem was seen in the vt_k_ioctl in drivers/tty/vt/vt_ioctl.c in the Linux kernel, which may cause an out of bounds read in vt as the write access to vc_mode is not protected by lock-in vt_ioctl (KDSETMDE). The highest threat from this vulnerability is to data confidentiality.

Understanding CVE-2021-3753

This CVE refers to a race problem in the Linux kernel that could lead to an out of bounds read vulnerability affecting data confidentiality.

What is CVE-2021-3753?

CVE-2021-3753 is a vulnerability found in the Linux kernel due to a race issue in vt_k_ioctl, potentially leading to unauthorized access to vc_mode and data confidentiality risks.

The Impact of CVE-2021-3753

The primary impact of CVE-2021-3753 is on data confidentiality, with the potential for unauthorized access due to the out of bounds read vulnerability.

Technical Details of CVE-2021-3753

This section provides detailed technical insights into the vulnerability.

Vulnerability Description

The vulnerability arises from a race issue in vt_k_ioctl, allowing unauthorized access to vc_mode and resulting in out of bounds read vulnerability.

Affected Systems and Versions

The affected system is the Linux kernel version 5.15-rc1, making it vulnerable to the race problem in vt_k_ioctl.

Exploitation Mechanism

Exploiting this vulnerability may result in unauthorized access to sensitive data through out of bounds read in vt.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-3753, certain steps need to be taken.

Immediate Steps to Take

Immediate actions involve monitoring for any unauthorized access and implementing access controls to restrict potential exploitation.

Long-Term Security Practices

Implementing a comprehensive security policy, regular vulnerability assessments, and security training can enhance long-term security measures.

Patching and Updates

Regularly updating the Linux kernel to eliminate the race problem in vt_k_ioctl is essential for preventing the exploitation of CVE-2021-3753.