CVE-2021-23337: Lodash Template Vulnerability Explained

by Alex Johnson 56 views

This article discusses the high-severity vulnerability, CVE-2021-23337, detected in lodash.template-4.5.0. This vulnerability affects projects using this version of the lodash library, specifically the _.template method. We will delve into the details of the vulnerability, its potential impact, and the recommended fix. This article will help you understand the vulnerability and how to mitigate the risks associated with it.

Understanding the Vulnerability

The vulnerability, CVE-2021-23337, is a command injection vulnerability found in Lodash versions prior to 4.17.21. Specifically, the _.template function is the point of attack. Lodash is a popular JavaScript utility library, and the _.template function is used for creating dynamic templates. This vulnerability allows an attacker to inject malicious code into the template, potentially leading to arbitrary command execution on the server.

Vulnerable Library: lodash.template-4.5.0.tgz

The vulnerable library is lodash.template-4.5.0.tgz. This version of the library is susceptible to command injection attacks due to the way the _.template function handles user-supplied input. The library can be found at https://registry.npmjs.org/lodash.template/-/lodash.template-4.5.0.tgz.

Dependency Path

In the context of the afwss/rover-ui project, the vulnerability was found through the following dependency path:

  • react-scripts-3.4.4.tgz (Root Library)
  • workbox-webpack-plugin-4.3.1.tgz
  • workbox-build-4.3.1.tgz
  • lodash.template-4.5.0.tgz (Vulnerable Library)

This path illustrates how the vulnerable lodash.template library is included as a transitive dependency in the project. Transitive dependencies can often be overlooked, making them a common source of security vulnerabilities. Understanding the dependency hierarchy is crucial for identifying and mitigating vulnerabilities effectively.

Location in Repository

The vulnerability was identified in the following commit of the afwss/rover-ui repository: aeab869031be23faba5c5de38e09f27a58e99471. It was also found in the base branch, master, indicating that the vulnerability is present in the main codebase. Identifying the specific commit helps developers pinpoint when the vulnerability was introduced and track the progress of remediation efforts.

Detailed Vulnerability Information

This section provides a more granular view of CVE-2021-23337, outlining the affected versions and the mechanics of the command injection vulnerability. It's vital to grasp these specifics to understand the severity and potential exploit scenarios.

Affected Versions

Lodash versions prior to 4.17.21 are vulnerable to this command injection. If your project uses a version of lodash older than 4.17.21, it is highly recommended to upgrade to the latest version or at least to version 4.17.21 to mitigate this vulnerability. This vulnerability arises due to the way the _.template function handles user-provided input. When processing templates, the function doesn't adequately sanitize or validate the input, creating an avenue for attackers to inject malicious code. By crafting specific input, an attacker can inject operating system commands that the server will execute, potentially leading to severe consequences such as data breaches, system compromise, or denial of service.

Command Injection via template Function

The _.template function in lodash is used to create templates that can dynamically generate text. However, if the input to this function is not properly sanitized, an attacker can inject arbitrary code. Command injection vulnerabilities are particularly dangerous because they allow an attacker to execute commands directly on the server. This could lead to complete system compromise, where the attacker gains full control over the server and its resources. The severity of such an attack depends on the privileges of the user running the application. If the application runs with administrative privileges, the attacker could perform almost any action on the system. This highlights the importance of minimizing the privileges granted to applications to reduce the potential impact of such vulnerabilities. Proper input validation and sanitization are crucial to preventing command injection attacks. Developers should always treat user input as potentially malicious and take steps to ensure that it cannot be used to execute arbitrary code. This includes escaping special characters, validating input against a whitelist, and using secure coding practices to avoid introducing vulnerabilities.

References

This link leads to the Mend vulnerability database, which offers detailed information about the vulnerability, including its description, affected versions, and remediation steps. It serves as a valuable resource for developers and security professionals seeking to understand and address the vulnerability.

CVSS 3 Score and Impact

Understanding the CVSS score helps in prioritizing the remediation efforts. A high CVSS score indicates a critical vulnerability that needs immediate attention.

CVSS 3 Score: 7.2 (High)

The vulnerability has a CVSS 3 score of 7.2, which is considered high severity. This score reflects the potential impact and exploitability of the vulnerability. A high CVSS score indicates that the vulnerability is relatively easy to exploit and can have significant consequences, such as data breaches, system compromise, or denial of service. The CVSS score is calculated based on several factors, including the attack vector, attack complexity, privileges required, user interaction, scope, confidentiality impact, integrity impact, and availability impact. Understanding these factors can help organizations prioritize their remediation efforts and allocate resources effectively.

Base Score Metrics

The CVSS 3 base score is calculated from several metrics, which provide a detailed understanding of the vulnerability's characteristics:

Exploitability Metrics:

  • Attack Vector: Network
    • The attack can be launched remotely over a network, making it easier to exploit.
  • Attack Complexity: Low
    • The vulnerability is easy to exploit, requiring little specialized knowledge or resources.
  • Privileges Required: High
    • The attacker needs high privileges to exploit the vulnerability, reducing the pool of potential attackers but increasing the potential damage.
  • User Interaction: None
    • No user interaction is required to trigger the vulnerability, making it more dangerous.
  • Scope: Unchanged
    • The vulnerability affects the same component, limiting the potential impact.

Impact Metrics:

  • Confidentiality Impact: High
    • The attacker can access sensitive information, leading to data breaches.
  • Integrity Impact: High
    • The attacker can modify data or system configurations, potentially compromising the entire system.
  • Availability Impact: High
    • The attacker can cause a denial of service, making the system unavailable to legitimate users.

These metrics provide a comprehensive view of the vulnerability, helping organizations understand the potential risks and prioritize their remediation efforts. By considering these factors, organizations can make informed decisions about how to address the vulnerability and protect their systems from attack.

CVSS v3 Calculator

For more information on CVSS3 Scores, click here.

This link directs to the CVSS v3 calculator, a tool that allows security professionals and developers to calculate CVSS scores based on various metrics. It provides a standardized way to assess the severity of vulnerabilities and prioritize remediation efforts. Using the calculator, organizations can input specific details about a vulnerability, such as the attack vector, complexity, and impact, to generate a CVSS score that reflects the vulnerability's overall severity. This score can then be used to guide decision-making and resource allocation, ensuring that the most critical vulnerabilities are addressed first.

Suggested Fix

The recommended solution is to upgrade to a version of lodash that is not affected by the vulnerability. Upgrading libraries is a crucial part of maintaining the security of any software project.

Type: Upgrade Version

The primary solution to address CVE-2021-23337 is to upgrade the lodash library to a version that includes the fix for this vulnerability. This ensures that the application is no longer susceptible to command injection attacks via the _.template function. Upgrading dependencies is a common and effective way to remediate security vulnerabilities in software projects. New versions often include bug fixes, security patches, and performance improvements, making it essential for maintaining the health and security of an application.

Resolution: lodash - 4.17.21, lodash-es - 4.17.21

The fix resolution indicates that lodash versions 4.17.21 and later, as well as lodash-es versions 4.17.21 and later, include the necessary patches to address the vulnerability. Therefore, projects using older versions should upgrade to at least version 4.17.21 to mitigate the risk. It's important to note that simply upgrading the lodash library may not be sufficient if other dependencies rely on the vulnerable version. In such cases, it may be necessary to update those dependencies as well or use dependency management tools to ensure that the correct version of lodash is used throughout the project. Dependency conflicts can sometimes occur during upgrades, so thorough testing is recommended to verify that the application functions correctly after the upgrade.

Upgrade Resources:

This link leads to the GitHub Advisory for the vulnerability, providing additional details, context, and recommendations. GitHub Advisories are a valuable resource for staying informed about security vulnerabilities and their remediation. The advisory typically includes information about the affected versions, the nature of the vulnerability, and steps to mitigate the risk. It may also provide links to related resources, such as security patches, blog posts, and discussions. By consulting the GitHub Advisory, developers and security professionals can gain a deeper understanding of the vulnerability and make informed decisions about how to address it. This is a crucial step in ensuring the security and integrity of software projects.

Conclusion

In conclusion, CVE-2021-23337 is a high-severity vulnerability that requires immediate attention. By upgrading to lodash version 4.17.21 or later, you can effectively mitigate the risk of command injection attacks. Always stay informed about the latest security vulnerabilities and ensure your dependencies are up to date. Staying proactive in addressing vulnerabilities is critical for maintaining the security and integrity of your software projects. Regular security audits, dependency checks, and adherence to secure coding practices can help prevent such issues from arising in the first place. Additionally, fostering a culture of security awareness within your development team can contribute to a more secure software development lifecycle.

For more information on security best practices, visit OWASP.