CVE-2021-22556 Explained : Impact and Mitigation

Integer Overflow in Fuchsia Kernel allows an attacker to control kernel memory from userspace. Upgrading to kernel version 4.1 or above is recommended.

Understanding CVE-2021-22556

This CVE refers to an integer overflow vulnerability found in the Fuchsia Kernel.

What is CVE-2021-22556?

The Security Team identified an integer overflow bug enabling attackers with code execution to perform memory cache invalidation operations on unauthorized pages, granting control of kernel memory from userspace.

The Impact of CVE-2021-22556

The vulnerability's impact is rated as medium severity, with a CVSS base score of 5.3. It poses a high confidentiality impact and low integrity impact with low privileges required.

Technical Details of CVE-2021-22556

This section covers the specific technical details of the CVE.

Vulnerability Description

The flaw in Fuchsia Kernel allows attackers to manipulate kernel memory from userspace, potentially leading to unauthorized access.

Affected Systems and Versions

The issue affects Fuchsia Kernel versions less than 4.1, particularly unspecified versions categorized as custom.

Exploitation Mechanism

Attackers with code execution can leverage the integer overflow bug to carry out memory cache invalidation operations on unowned pages, granting control over kernel memory.

Mitigation and Prevention

To address CVE-2021-22556, immediate actions and long-term security practices are crucial.

Immediate Steps to Take

Upgrading to kernel version 4.1 or higher is advised to mitigate the vulnerability and enhance system security.

Long-Term Security Practices

Developing a robust security posture, including regular vulnerability assessments and security updates, is essential to safeguard against similar threats.

Patching and Updates

Regularly applying security patches and updates to the Fuchsia Kernel is critical to addressing known vulnerabilities and enhancing system defenses.