CVE-2023-40238 : Security Advisory and Response

A LogoFAIL issue was discovered in BmpDecoderDxe in Insyde InsydeH2O with kernel 5.2 before 05.28.47, 5.3 before 05.37.47, 5.4 before 05.45.47, 5.5 before 05.53.47, and 5.6 before 05.60.47 for certain Lenovo devices.

Understanding CVE-2023-40238

This CVE refers to a vulnerability in the image parsing mechanism of certain Lenovo devices that allows crafted BMP logo files to copy data to a specific address during the DXE phase of UEFI execution due to an integer signedness error.

What is CVE-2023-40238?

CVE-2023-40238, known as LogoFAIL, allows attackers to exploit an integer signedness error during RLE4/RLE8 compression of BMP logo files, potentially leading to unauthorized data copying.

The Impact of CVE-2023-40238

This vulnerability can be exploited by malicious actors to execute arbitrary code or cause a denial of service (DoS) on affected Lenovo devices, compromising system integrity and confidentiality.

Technical Details of CVE-2023-40238

The following technical details shed light on the nature of the vulnerability:

Vulnerability Description

The vulnerability arises from an integer signedness error involving PixelHeight and PixelWidth during RLE4/RLE8 compression, enabling data copying to a specific address.

Affected Systems and Versions

All Lenovo devices with InsydeH2O kernel versions 5.2 to 5.6 before the specified patch releases are vulnerable to this LogoFAIL issue.

Exploitation Mechanism

Attackers can exploit the vulnerability by creating specially crafted BMP logo files to trigger the data copying mechanism during the DXE phase of UEFI execution.

Mitigation and Prevention

To mitigate the risks associated with CVE-2023-40238, consider the following steps:

Immediate Steps to Take

Apply the patches provided by Insyde for the affected kernel versions to address the vulnerability.
Restrict access to system boot procedures and UEFI execution to prevent unauthorized code execution.

Long-Term Security Practices

Regularly update system firmware and software to protect against known vulnerabilities.
Implement secure coding practices to prevent integer signedness errors in image parsing mechanisms.

Patching and Updates

Stay informed about security advisories from Insyde, Lenovo, and relevant authorities to promptly apply patches and updates to secure your devices.