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A closer look: Differentiating software vulnerabilities and malware

July 11, 2023 By Aaron Linskens

6 minute read time

In today’s interconnected digital world, vulnerabilities and malware in open source software pose significant threats to the security and integrity of your software supply chain. While these two terms may appear synonymous at first glance, you should know their fundamental differences. They are two distinct yet closely related aspects of cybersecurity.

In the context of open source software, vulnerabilities refer to security flaws that can be exploited, while malware concerns malicious components that intentionally insert harmful code into open source projects.

This blog post sheds light on the dissimilarities between software vulnerabilities and malicious open source, highlighting their unique characteristics, means of exploitation, and impact in open source software.

Software vulnerability: A flaw in the code

A software vulnerability is akin to a flaw in code, much like a faulty lock on a door. However, unlike malware, vulnerabilities are not intentional. Instead, they represent weaknesses in software components or projects.

Similar to how a faulty lock compromises the security of a building by allowing unauthorized access, a software vulnerability creates a gap in the software's security perimeter. This gap becomes an entry point for intruders to exploit, gaining unapproved access to the system, application, or component.

Much like how an intruder can bypass a faulty lock to enter a building without a key, threat actors exploit vulnerabilities to compromise the software. This exploitation can result in severe consequences, such as surreptitious data access, injection of malicious code, or disruption of the software's intended functionality.

Vulnerabilities can exist in various software components, such as: 

  • operating systems
  • applications
  • libraries
  • plugins

Typically, vulnerabilities originate from coding errors, design flaws, or inadequate security measures during software development. Once identified, vulnerabilities typically receive a special identifier number from the Common Vulnerabilities and Exposures (CVE) program. This CVE number serves as a shorthand reference for tracking and discussing the vulnerability.

Efficiently identifying and addressing software vulnerabilities is crucial to ensure the security and reliability of your software supply chain and protect against potential breaches.

Examples of software vulnerabilities

Below we cover a few real-life examples to better understand software vulnerabilities.


Heartbleed (CVE-2014-0160) was a critical vulnerability discovered in the OpenSSL cryptographic software library in April 2014. This vulnerability allowed threat actors to exploit a flaw in the implementation of the Transport Layer Security (TLS) Heartbeat extension, potentially exposing sensitive information like usernames, passwords, and private encryption keys.

The Heartbleed vulnerability affected a vast amount of web servers and required prompt patching for mitigation.


The Log4Shell vulnerability (CVE-2021-44228) affected a widely used open source logging library called Log4j. Threat actors could take advantage of this vulnerability by sending specially crafted log messages, which allowed them to remotely execute malicious code.

This vulnerability greatly affected and continues to affect many organizations across the world. It highlighted the need for quick action and constant vigilance to address vulnerabilities, even in trusted libraries.


Another notable vulnerability (CVE-2022-22965) targeted the popular Spring Framework used in Java applications. Spring4Shell was a zero-day vulnerability, meaning that threat actors exploited it before a fix was available.

This incident illustrated the importance of staying updated with the latest security patches and being aware of evolving threats in open source components.

Malware: Malicious intent in open source

Malware, short for “malicious software,” poses a significant threat to open source software ecosystems. It encompasses a wide range of malicious programs, such as viruses, worms, trojans, ransomware, spyware, and adware, all designed to gain unauthorized access to information or systems.

With its various forms, malware’s primary purpose is to steal data, install harmful software, gain control of a network, or compromise software or hardware. Threat actors employ diverse distribution methods, such as infected email attachments, malicious websites, or compromised software downloads.

One particularly concerning aspect of malware is the emergence of “malicious open source” or malicious packages. These appear legitimate but actually contain hidden harmful code. Developers unknowingly incorporate malicious open source into their software, allowing malware to enter their systems. It’s like receiving a package in the mail that appears innocent but contains something harmful. And once you open it, the damage is done.

Unlike a vulnerability, tracking and mitigating malicious open source can be challenging. Malicious packages in particular are often distributed through public package repositories, and when discovered, can be removed. But they usually don’t receive a CVE number, which makes it difficult to fully understand the extent of the threat to protect any affected systems.

Examples of malware

Below we cover a few examples of malware to illustrate how malicious packages can cause harm.

NotPetya ransomware

In 2017, the NotPetya ransomware attack occurred. The attack began in Ukraine and quickly spread to other countries, infecting international shipping container company Maersk, e-commerce and transportation conglomerate FedEx, and pharmaceutical company Merck.

NotPetya used stolen credentials and exploits to spread across networks, encrypting data. The attackers behind the attack initially targeted Ukrainian government and business networks, but the malware soon spread beyond Ukraine and caused significant disruption to businesses around the world.

The incident highlighted the potential impact of a large-scale ransomware attack on global business operations, as well as the importance of effective cybersecurity measures such as multi-factor authentication and regular backups to mitigate the risk of data loss.

Stuxnet worm

Stuxnet was a sophisticated computer worm discovered in 2010. It targeted supervisory control and data acquisition (SCADA) systems used in industrial environments, specifically Iran’s nuclear program.

The worm spread through USB drives and exploited multiple zero-day vulnerabilities to infiltrate the target systems. Stuxnet showcased the capability of nation-state threat actors to develop and deploy malware for covert operations, marking a new era of cyber warfare.

WannaCry ransomware

In May 2017, WannaCry emerged as a highly disruptive ransomware attack that affected hundreds of thousands of computers worldwide. This malware exploited a vulnerability in the Microsoft Windows operating system, leveraging the EternalBlue exploit, which was allegedly developed by the National Security Administration (NSA).

Once inside a system, WannaCry encrypted files and demanded a ransom in exchange for decryption, causing significant damage to the computing systems of organizations and individuals.

Protect your software: Defense against vulnerabilities and malicious open source

While software vulnerabilities and malicious open source share a connection as security risks, knowing the difference is critical to effectively managing your open source components and protecting your software supply chain. Understanding this distinction helps you take appropriate measures to prevent and mitigate both vulnerabilities and malware threats. Depending on your software supply chain’s level of maturity, software composition analysis (SCA) solutions that automate detection and protection could give you a leg up on threat actors.

Sonatype Lifecycle focuses on vulnerability management throughout the software development life cycle (SDLC). It integrates seamlessly into your development environment, enabling early detection of vulnerabilities in open source components. With continuous monitoring and policy enforcement, Lifecycle helps prevent the incorporation of unapproved components, promotes secure coding practices, and enables you to fix open source vulnerabilities across the SDLC.

In terms of malicious open source, Sonatype Repository Firewall acts as a first line of defense that prevents malicious components from entering your software supply chain. It automatically blocks malicious packages from entering your systems, significantly reducing the risk of compromise and data breaches. With its advanced threat intelligence, it stays up-to-date with the latest malware signatures, providing proactive protection against emerging threats.

With Sonatype Repository Firewall and Sonatype Lifecycle, you defend against the ever-present threats of malicious open source and vulnerabilities to ensure the security and reliability of your software supply chain. By prioritizing software security and adopting the right tools, you can confidently deliver secure applications to your users, mitigating the risk of breaches and preserving your organization's reputation.

Tags: vulnerabilities, Software Supply Chain, Open Source, malware prevention, DevZone, Sonatype Lifecycle, Sonatype Repository Firewall

Written by Aaron Linskens

Aaron is a technical writer on Sonatype's Developer Relations team. He works at a crossroads of technical writing, developer advocacy, software development, and open source. He aims to get developers and non-technical collaborators to work well together via experimentation, feedback, and iteration so they can build the right software.