CVE-2020-28974 : Exploit Details and Defense Strategies

A slab-out-of-bounds read vulnerability in fbcon in the Linux kernel before version 5.9.7 could allow local attackers to access privileged information or potentially crash the kernel.

Understanding CVE-2020-28974

This CVE identifies a specific security issue in the Linux kernel that could be exploited by attackers.

What is CVE-2020-28974?

The vulnerability in fbcon in the Linux kernel before 5.9.7 allows local attackers to perform a slab-out-of-bounds read, potentially leading to the disclosure of sensitive information or causing a kernel crash.

The Impact of CVE-2020-28974

The vulnerability could be exploited by malicious actors to read privileged data or disrupt the kernel's operation, posing a risk to system integrity and confidentiality.

Technical Details of CVE-2020-28974

This section delves into the technical aspects of the CVE.

Vulnerability Description

The issue arises from a slab-out-of-bounds read in fbcon, specifically in the KD_FONT_OP_COPY function in drivers/tty/vt/vt.c within the Linux kernel.

Affected Systems and Versions

Affected systems: Linux kernel versions before 5.9.7
Affected components: fbcon driver

Exploitation Mechanism

Attackers with local access can leverage the vulnerability in fbcon to read privileged information or potentially crash the kernel by manipulating font height using KD_FONT_OP_COPY.

Mitigation and Prevention

Protecting systems from CVE-2020-28974 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply security updates and patches promptly to mitigate the vulnerability.
Monitor for any unusual system behavior that could indicate exploitation.

Long-Term Security Practices

Implement the principle of least privilege to restrict access rights for users and processes.
Regularly review and update security configurations to enhance system resilience.

Patching and Updates

Update the Linux kernel to version 5.9.7 or newer to address the vulnerability in fbcon.