Understanding CVE-2019-9674: Mitigating Denial of Service Attack via ZIP Bomb in Python

Welcome to an in-depth look at CVE-2019-9674, a significant security vulnerability identified in Python, one of the world’s most popular programming languages, known for its versatility and robust libraries. This issue is specifically found in the 'zipfile.py' module and has been classified with a high severity score of 7.5. Our discussion today aims to enlighten LinuxPatch users about the nature of the vulnerability, its potential impacts, and how to effectively mitigate this risk.

A Brief Overview of CVE-2019-9674

The CVE-2019-9674 pertains to the 'Lib/zipfile.py' module in versions of Python up to 3.7.2. It exposes a vulnerability where remote attackers can cause a Denial of Service (DoS) via a ZIP bomb. A ZIP bomb is a malformed ZIP archive with an enormous size ratio once decompressed. This can exhaust system resources, leading to denial of service.

Details of the Vulnerability

This vulnerability arises due to the absence of proper validation mechanisms when processing ZIP archive files. Malicious actors can exploit this by crafting a ZIP file that, upon extraction, consumes excessive computational resources. The effect is more pronounced on systems with limited processing capabilities or those handling large volumes of data, such as web servers or data analysis platforms.

Impact on Systems

The direct outcome of this vulnerability is the potential to grind affected systems to a halt, thereby disrupting operations and accessing services. Systems that extensively use Python for tasks like data processing or web services are particularly at risk. Given Python's widespread adoption across various industries, the impacts of such a vulnerability can be far-reaching, affecting multiple sectors concurrently.

Software and Systems Affected

All systems utilizing versions of Python up to 3.7.2 and relying on the zipfile module for processing ZIP files are vulnerable. This includes applications across both Linux and other operating systems where Python is utilized.

Immediate Actions and Mitigation

To protect your systems from CVE-2019-9674, it is crucial to apply patches and updates immediately. Python has addressed this vulnerability in subsequent releases following version 3.7.2. System administrators and developers should ensure that the latest secure versions of Python are deployed, especially in environments where ZIP files are regularly processed.

Additionally, consider implementing safety checks around file handling procedures to preemptively screen ZIP files for characteristics typical of ZIP bombs. Such measures can significantly enhance your resilience against similar attacks.How LinuxPatch Can Help

At LinuxPatch, we specialize in providing comprehensive patch management solutions for Linux servers, ensuring your systems are protected against vulnerabilities like CVE-2019-9674. Our platform facilitates seamless updates and is designed to help you maintain security with minimal disruption to your operations.


In conclusion, while the CVE-2019-9674 presents a critical challenge, understanding and proactive management can effectively mitigate risks. We encourage all users to update their systems and to leverage patch management tools like LinuxPatch to secure and optimize their server environments against potential threats.

For more detailed information on how LinuxPatch can assist you in defending against vulnerabilities and ensuring your systems are up to date, visit our website.