CVE-2021-28856 Explained : Impact and Mitigation

Deark before v1.5.8 is vulnerable to a division by zero due to a specially crafted input file. This vulnerability occurs in (src/fmtutil.c) because of the value of pixelsize.

Understanding CVE-2021-28856

This CVE highlights a vulnerability in Deark that could be exploited by a specially crafted input file to trigger a division by zero error.

What is CVE-2021-28856?

CVE-2021-28856 is a vulnerability in Deark before v1.5.8 that allows an attacker to exploit a division by zero issue by using a malicious input file.

The Impact of CVE-2021-28856

This vulnerability could lead to a denial of service (DoS) condition where an attacker could potentially crash the affected system by exploiting the division by zero flaw.

Technical Details of CVE-2021-28856

In Deark before v1.5.8, the issue resides in (src/fmtutil.c) and is triggered by the manipulation of the pixelsize value in a specially crafted input file.

Vulnerability Description

The vulnerability arises due to improper handling of the pixelsize value, leading to a division by zero error.

Affected Systems and Versions

All versions of Deark before v1.5.8 are affected by this vulnerability.

Exploitation Mechanism

An attacker can exploit this vulnerability by creating a specially crafted input file that manipulates the pixelsize value to trigger the division by zero error.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-28856, users and administrators are advised to take the following actions:

Immediate Steps to Take

Update Deark to version 1.5.8 or later to address the division by zero vulnerability.
Avoid opening untrusted or suspicious input files to prevent potential exploitation.

Long-Term Security Practices

Regularly update software and applications to the latest versions to patch known vulnerabilities.
Implement strong input validation mechanisms to prevent malformed files from causing security issues.

Patching and Updates

Deark users should prioritize applying patches and updates provided by the vendor to ensure the security of their systems.