CVE-2022-28737 : Vulnerability Insights and Analysis

A possible overflow vulnerability in handle_image() when loading and executing crafted EFI executables via shim affecting Linux platforms.

Understanding CVE-2022-28737

This CVE highlights a vulnerability in the handle_image() function of shim that could be exploited by an attacker to perform out-of-bound writes into memory, potentially leading to arbitrary code execution.

What is CVE-2022-28737?

The CVE-2022-28737 vulnerability involves an overflow in the handle_image() function of shim, specifically when loading and executing maliciously crafted EFI executables. By manipulating the SizeOfRawData field from each section, an attacker can trigger out-of-bound writes, posing a risk of arbitrary code execution.

The Impact of CVE-2022-28737

The impact of CVE-2022-28737 is significant, with the potential for high confidentiality, integrity, and availability impacts. An attacker exploiting this vulnerability could execute arbitrary code, compromising the security and stability of the affected systems.

Technical Details of CVE-2022-28737

This section provides detailed technical insights into the vulnerability.

Vulnerability Description

The vulnerability arises from a lack of proper input validation in the handle_image() function, allowing attackers to manipulate memory through crafted EFI executables.

Affected Systems and Versions

The vulnerability affects systems running the shim bootloader with versions less than 15.6 on Linux platforms.

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting EFI executables with manipulated SizeOfRawData fields, triggering out-of-bound writes in memory upon loading by the handle_image() function.

Mitigation and Prevention

Take immediate steps to address the CVE and implement long-term security practices.

Immediate Steps to Take

Update the shim bootloader to version 15.6 or above to mitigate the vulnerability.
Monitor for any unusual activities that could indicate exploitation of the handle_image() overflow.

Long-Term Security Practices

Regularly update all system components to ensure the latest security patches are applied.
Conduct security assessments and audits to identify and remediate vulnerabilities proactively.

Patching and Updates

Stay informed about security updates and patches released by the vendor to address CVE-2022-28737 and other potential threats.