CVE-2025-12758: High Vulnerability In Validator-13.7.0

by Alex Johnson 55 views

This article delves into the critical CVE-2025-12758 vulnerability detected in validator-13.7.0.tgz, a widely-used library for string validation and sanitization. Understanding the nature of this vulnerability, its potential impact, and the recommended fix is crucial for developers and organizations relying on this library. We will explore the details of this high-severity issue, offering insights into its causes and the steps needed to mitigate the risk. Let's dive in and ensure your applications remain secure.

Vulnerability Overview

The CVE-2025-12758 vulnerability is a high-severity issue found in the validator-13.7.0.tgz library. This library, commonly used for string validation and sanitization, has a flaw in its isLength() function that can lead to significant security concerns. The core issue lies in the incomplete filtering of special elements within the isLength() function, specifically related to Unicode variation selectors. This vulnerability was identified and reported, emphasizing the need for immediate attention and action from developers and system administrators.

Key Details:

The vulnerability stems from the fact that the isLength() function does not properly account for Unicode variation selectors (\uFE0F, \uFE0E) in a sequence. This oversight can result in an inaccurate calculation of string length, leading to several potential security breaches. An application using isLength for input validation might accept strings that are significantly longer than intended. This can lead to problems such as data truncation in databases, buffer overflows in other system components, and even denial-of-service (DoS) attacks. It’s crucial to understand these implications to appreciate the severity and potential impact of this vulnerability.

Technical Analysis of CVE-2025-12758

To fully grasp the implications of CVE-2025-12758, a technical dive into the vulnerability is essential. The core of the issue resides in the isLength() function within the validator library. This function is designed to validate whether a string's length falls within specified bounds. However, the vulnerability arises due to the function's failure to properly handle Unicode variation selectors. These selectors, such as \uFE0F and \uFE0E, are used to specify a particular variant of a Unicode character. The isLength() function incorrectly calculates the string length when these selectors are present, leading to a discrepancy between the intended and actual length.

Root Cause: Incomplete Filtering of Unicode Variation Selectors

Unicode variation selectors are characters that modify the appearance of the preceding character. When the isLength() function encounters these selectors, it does not exclude them from the length calculation. Consequently, a string that appears to be within the specified length constraints may, in reality, exceed those limits when the variation selectors are properly accounted for. This miscalculation can have far-reaching consequences, especially in scenarios where the validated string is used in subsequent operations such as database entries or buffer allocations.

Impact Scenarios:

  1. Data Truncation: If a database field has a length constraint, an overlong string (as perceived by the flawed isLength() function) could be truncated upon insertion, leading to data loss or corruption.
  2. Buffer Overflows: In cases where the string is used to allocate a buffer, the incorrect length calculation can result in a buffer overflow, potentially leading to arbitrary code execution.
  3. Denial-of-Service (DoS): A malicious actor could exploit this vulnerability to send extremely long strings that pass the isLength() validation but cause the application to consume excessive resources, leading to a denial of service.

Dependency Hierarchy

The vulnerability is deeply embedded within the dependency hierarchy of many projects. As detailed in the provided information, the vulnerable library is found within the following chain:

sails-1.5.3.tgz (Root Library)
└── machine-15.2.2.tgz
    └── anchor-1.4.1.tgz
        └── validator-13.7.0.tgz (Vulnerable Library)

This hierarchy illustrates that even projects that do not directly use validator-13.7.0.tgz can be vulnerable if they depend on libraries that, in turn, depend on the flawed validator version. This transitive dependency makes the vulnerability widespread and highlights the importance of thorough dependency scanning and management.

Impact and Severity

The impact of CVE-2025-12758 is significant due to the widespread use of the validator library in numerous applications. The vulnerability allows for the potential bypass of input validation, leading to various security issues. Data truncation can occur when an application accepts a string that exceeds the intended length, resulting in loss or corruption of data. Buffer overflows can also arise, potentially allowing for arbitrary code execution. Furthermore, the vulnerability can be exploited to launch denial-of-service (DoS) attacks by sending maliciously crafted strings that exhaust system resources. Understanding the severity of this vulnerability is crucial for prioritizing remediation efforts.

CVSS 3 Score: 7.5 (High Severity)

The Common Vulnerability Scoring System (CVSS) provides a standardized way to assess the severity of security vulnerabilities. CVE-2025-12758 has been assigned a CVSS 3 score of 7.5, indicating a high-severity vulnerability. This score reflects the potential for significant impact and the relative ease of exploitation. The CVSS 3 score is broken down into several metrics, each contributing to the overall score.

Base Score Metrics:

The base score is calculated based on the intrinsic characteristics of the vulnerability, independent of environmental factors. The key metrics include:

  • Exploitability Metrics: These metrics assess the ease and means by which the vulnerability can be exploited.
    • Attack Vector: Network: The vulnerability can be exploited over a network, increasing its accessibility.
    • Attack Complexity: Low: The complexity required to exploit the vulnerability is low, making it easier to carry out an attack.
    • Privileges Required: None: No privileges are required to exploit the vulnerability, meaning an attacker can exploit it without needing any credentials.
    • User Interaction: None: No user interaction is required to trigger the vulnerability, allowing for automated exploitation.
    • Scope: Unchanged: An exploitation of the vulnerability affects a resource managed by the same security authority as the vulnerable component.
  • Impact Metrics: These metrics assess the potential impact on confidentiality, integrity, and availability.
    • Confidentiality Impact: None: There is no impact on confidentiality, meaning the vulnerability does not allow an attacker to access sensitive information.
    • Integrity Impact: None: There is no impact on integrity, meaning the vulnerability does not allow an attacker to modify data.
    • Availability Impact: High: The vulnerability can lead to a significant disruption of service, potentially causing a denial-of-service condition.

The high availability impact, combined with the low attack complexity and lack of required privileges or user interaction, contributes to the high CVSS score. This underscores the urgent need for organizations to address this vulnerability promptly.

Remediation and Mitigation

Addressing CVE-2025-12758 is crucial for maintaining the security and stability of applications using the validator library. The primary remediation strategy is to upgrade to a patched version of the library. The suggested fix is to upgrade to version 13.15.22 or later, where the vulnerability has been addressed. Upgrading ensures that the isLength() function correctly handles Unicode variation selectors, preventing the miscalculation of string lengths. This upgrade effectively mitigates the risks associated with data truncation, buffer overflows, and denial-of-service attacks.

Upgrade Instructions:

The recommended fix resolution includes:

  • Upgrade to validator version 13.15.22 or later.
  • Use the specific Git repository version: https://github.com/validatorjs/validator.js.git - 13.15.22

The upgrade process typically involves updating the dependency in your project's package manager configuration (e.g., package.json for Node.js projects) and running the appropriate update command (e.g., npm install or yarn upgrade). It is essential to verify that the upgraded version is correctly installed and that all dependencies are compatible.

Mitigation Steps:

In addition to upgrading, several mitigation steps can be taken to further reduce the risk:

  1. Input Validation: Implement robust input validation routines in your application. Even with the patched library, additional validation can provide an extra layer of security.
  2. Web Application Firewall (WAF): Deploy a WAF to filter out malicious requests that attempt to exploit this vulnerability. A WAF can identify and block patterns indicative of exploitation attempts.
  3. Regular Security Audits: Conduct regular security audits and penetration testing to identify and address potential vulnerabilities in your applications.
  4. Dependency Scanning: Use automated dependency scanning tools to detect vulnerable libraries in your project. These tools can alert you to known vulnerabilities and suggest remediation steps.

Example Upgrade Process (Node.js):

  1. Update package.json:

    "dependencies": {
"validator": "^13.15.22",
// other dependencies
}

  2. Run npm install or yarn upgrade:

    npm install

    or

    yarn upgrade validator

By following these remediation and mitigation steps, organizations can significantly reduce their exposure to CVE-2025-12758 and protect their applications from potential attacks. Prioritizing the upgrade to version 13.15.22 or later is the most effective way to address this vulnerability.

Conclusion

The CVE-2025-12758 vulnerability in validator-13.7.0.tgz poses a significant risk to applications that rely on this library for string validation. The incomplete filtering of Unicode variation selectors in the isLength() function can lead to data truncation, buffer overflows, and denial-of-service attacks. The high CVSS score of 7.5 underscores the severity of this vulnerability, necessitating prompt action from developers and organizations.

To mitigate the risks associated with CVE-2025-12758, upgrading to validator version 13.15.22 or later is essential. This upgrade ensures that the isLength() function correctly handles Unicode variation selectors, preventing the miscalculation of string lengths. Additionally, implementing robust input validation routines, deploying a Web Application Firewall (WAF), conducting regular security audits, and using automated dependency scanning tools can further enhance security posture.

By understanding the technical details of the vulnerability, its potential impact, and the recommended remediation steps, developers and organizations can effectively protect their applications from exploitation. Prioritizing security and staying informed about vulnerabilities are crucial aspects of maintaining a secure software ecosystem.

For more information on vulnerability management and security best practices, visit the National Institute of Standards and Technology (NIST) website.