EUVD-2025-37820

Comprehensive Technical Analysis of EUVD-2025-37820

1. Vulnerability Assessment and Severity Evaluation

The vulnerability described in EUVD-2025-37820 pertains to the expr-eval library, a JavaScript expression parser and evaluator. The core issue is insufficient input validation, which allows an attacker to pass a crafted variables object into the evaluate() function, leading to arbitrary code execution.

Severity Evaluation:

• Base Score: 9.8 (Critical)
• Base Score Version: CVSS 3.1
• Base Score Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

The high base score indicates a critical vulnerability due to the following factors:

• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): None (N)
• Scope (S): Unchanged (U)
• Confidentiality (C): High (H)
• Integrity (I): High (H)
• Availability (A): High (H)

This vulnerability can be exploited remotely without requiring any special privileges or user interaction, making it highly dangerous.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Remote Code Execution (RCE): An attacker can craft a malicious input to the evaluate() function, leading to arbitrary code execution on the server.
• Supply Chain Attack: If the vulnerable library is used in a larger application, an attacker could exploit this vulnerability to compromise the entire application.

Exploitation Methods:

• Crafted Input: An attacker can create a specially crafted variables object that, when passed to the evaluate() function, executes arbitrary code.
• Injection Attacks: By injecting malicious code through the variables object, an attacker can gain control over the system.

3. Affected Systems and Software Versions

Affected Software:

• expr-eval versions 0 ≤ 2.0.2
• expr-eval-fork versions 0 ≤ 2.0.2

Affected Systems:

• Any system or application that uses the expr-eval or expr-eval-fork library in versions up to and including 2.0.2.

4. Recommended Mitigation Strategies

Immediate Mitigation:

• Update to a Patched Version: Upgrade to a version of expr-eval or expr-eval-fork that addresses this vulnerability.
• Input Validation: Implement additional input validation and sanitization to prevent malicious inputs from being processed.

Long-Term Mitigation:

• Code Review: Conduct a thorough code review to identify and fix similar vulnerabilities.
• Security Training: Educate developers on secure coding practices to prevent future vulnerabilities.
• Regular Updates: Ensure that all dependencies are regularly updated to their latest versions.

5. Impact on European Cybersecurity Landscape

The vulnerability in expr-eval poses a significant risk to the European cybersecurity landscape, particularly for organizations that rely on JavaScript libraries for mathematical evaluations. The potential for arbitrary code execution can lead to data breaches, system compromises, and loss of service availability. This underscores the importance of robust input validation and regular security audits of third-party libraries.

6. Technical Details for Security Professionals

Vulnerability Details:

• Library: expr-eval
• Function: evaluate()
• Issue: Insufficient input validation
• Exploit: Crafted variables object leading to arbitrary code execution

References:

• NVD: CVE-2025-12735
• GitHub Pull Request: Pull Request #288
• GitHub Repositories:
  • silentmatt/expr-eval
  • jorenbroekema/expr-eval
• NPM Packages:
  • expr-eval
  • expr-eval-fork

Aliases:

• CVE: CVE-2025-12735
• GHSA: GHSA-jc85-fpwf-qm7x

Assigner:

• certcc

ENISA ID Product:

• expr-eval-fork versions 0 ≤ 2.0.2
• expr-eval versions 0 ≤ 2.0.2

ENISA ID Vendor:

• expr-eval-fork
• silentmatt

Conclusion: This vulnerability highlights the critical importance of input validation and the need for continuous monitoring and updating of third-party libraries. Organizations should prioritize patching affected systems and implementing robust security measures to mitigate similar risks in the future.