CVE-2021-28675 : What You Need to Know

An issue was discovered in Pillow before 8.2.0 related to PSDImagePlugin.PsdImageFile. This vulnerability lacked a sanity check on the number of input layers, potentially leading to a Denial of Service (DoS) on Image.open prior to Image.load.

Understanding CVE-2021-28675

This section provides an overview of the key details regarding the CVE-2021-28675 vulnerability.

What is CVE-2021-28675?

CVE-2021-28675 is a vulnerability found in Pillow before version 8.2.0 that results from a missing sanity check within the PSDImagePlugin.PsdImageFile component. The absence of this check could allow an attacker to trigger a DoS condition on the Image.open function before loading the image.

The Impact of CVE-2021-28675

The impact of CVE-2021-28675 is the potential for a DoS attack, which could disrupt the normal functioning of the Image.open operation, affecting applications utilizing this vulnerable component.

Technical Details of CVE-2021-28675

In this section, we delve into the technical specifics of the CVE-2021-28675 vulnerability.

Vulnerability Description

The vulnerability arises from a failure in the PSDImagePlugin.PsdImageFile to implement a proper check on the number of input layers relative to the size of the data block, leading to the risk of DoS.

Affected Systems and Versions

All versions of Pillow before 8.2.0 are affected by this vulnerability, making them susceptible to exploitation if not updated.

Exploitation Mechanism

The exploitation of CVE-2021-28675 involves an attacker crafting a malicious input that can trigger the absence of the expected sanity check, initiating a DoS condition.

Mitigation and Prevention

This section outlines the steps to mitigate and prevent the CVE-2021-28675 vulnerability.

Immediate Steps to Take

Immediate actions include updating to Pillow version 8.2.0 or later to remediate the vulnerability and prevent potential DoS attacks.

Long-Term Security Practices

Implementing secure coding practices, conducting regular security audits, and staying informed about security advisories are essential for maintaining long-term resilience against emerging vulnerabilities.

Patching and Updates

Regularly checking for software updates, especially security patches for third-party dependencies like Pillow, is crucial to ensure that known vulnerabilities are promptly addressed.