CVE-2021-27799 : Exploit Details and Defense Strategies

A stack-based buffer overflow vulnerability exists in Zint Barcode Generator 2.9.1, specifically in the ean_leading_zeroes function within backend/upcean.c. This vulnerability can be exploited through an application incorporating the Zint Barcode Generator library code.

Understanding CVE-2021-27799

This CVE record highlights a critical security flaw in the Zint Barcode Generator that could lead to potential exploitation.

What is CVE-2021-27799?

The vulnerability identified as CVE-2021-27799 is a stack-based buffer overflow in the Zint Barcode Generator version 2.9.1. When the ean_leading_zeroes function in backend/upcean.c is accessed through the C API, it becomes susceptible to exploitation.

The Impact of CVE-2021-27799

Exploitation of this vulnerability could allow an attacker to execute arbitrary code or crash the application, leading to a denial of service (DoS) condition. This could pose a significant risk to the security and stability of systems using the affected Zint Barcode Generator.

Technical Details of CVE-2021-27799

This section delves into the specific technical aspects of the CVE-2021-27799 vulnerability.

Vulnerability Description

The vulnerability arises from a stack-based buffer overflow in the ean_leading_zeroes function of the Zint Barcode Generator version 2.9.1. By manipulating the particularly crafted application data, an attacker could trigger this overflow, potentially leading to the execution of malicious code.

Affected Systems and Versions

Zint Barcode Generator version 2.9.1 is confirmed to be impacted by this vulnerability. No other specific products or versions are reported to be affected.

Exploitation Mechanism

Exploiting this vulnerability requires the involvement of an application that integrates the Zint Barcode Generator library code. Through manipulation of the ean_leading_zeroes function in backend/upcean.c, an attacker can abuse the buffer overflow to initiate malicious activities.

Mitigation and Prevention

To safeguard systems from the CVE-2021-27799 vulnerability, proactive measures need to be implemented.

Immediate Steps to Take

Users are advised to refrain from using the affected version of the Zint Barcode Generator until a patch is available.
Employ network security measures to minimize the risk of exploitation through external access.

Long-Term Security Practices

Regularly monitor for security updates and patches released by Zint Barcode Generator to address vulnerabilities promptly.

Patching and Updates

Stay informed about security advisories from Zint Barcode Generator and apply patches as soon as they are made available to ensure protection against CVE-2021-27799.