CVE-2025-6545 Overview
CVE-2025-6545 is an Improper Input Validation vulnerability in the pbkdf2 npm package that allows Signature Spoofing by Improper Validation. This vulnerability is associated with program files lib/to-buffer.js and affects pbkdf2 versions from 3.0.10 through 3.1.2.
The pbkdf2 package is a JavaScript implementation of the Password-Based Key Derivation Function 2 (PBKDF2), commonly used in the browserify ecosystem for cryptographic operations in browser environments. Due to improper input validation in the to-buffer.js module, attackers can potentially spoof signatures, undermining the cryptographic integrity that applications relying on this library depend upon.
Critical Impact
This vulnerability enables signature spoofing through improper input validation, potentially allowing attackers to bypass authentication mechanisms or forge cryptographic signatures in applications using affected versions of the pbkdf2 library.
Affected Products
- pbkdf2 versions 3.0.10 through 3.1.2
- Applications using browserify with vulnerable pbkdf2 dependency
- Node.js applications importing affected pbkdf2 versions
Discovery Timeline
- June 23, 2025 - CVE-2025-6545 published to NVD
- June 23, 2025 - Last updated in NVD database
Technical Details for CVE-2025-6545
Vulnerability Analysis
This vulnerability stems from improper input validation (CWE-20) within the lib/to-buffer.js file of the pbkdf2 package. The to-buffer.js module is responsible for converting various input types into Buffer objects for cryptographic operations. When input validation is insufficient, attackers can craft malicious inputs that pass through the validation checks incorrectly, leading to signature spoofing conditions.
The impact of this vulnerability is significant for cryptographic applications. PBKDF2 is widely used for password hashing and key derivation. When the input validation fails to properly handle certain edge cases, it can result in predictable or manipulable cryptographic outputs, allowing an attacker to forge valid signatures without possessing the original key material.
Applications that use pbkdf2 for authentication tokens, password verification, or cryptographic signing operations are at particular risk. The network-accessible nature of this vulnerability means that remote attackers can potentially exploit it without requiring any privileges or user interaction.
Root Cause
The root cause of CVE-2025-6545 lies in the lib/to-buffer.js module's failure to properly validate and sanitize input data before processing. The improper input validation allows specially crafted inputs to be processed in unexpected ways, leading to signature spoofing conditions. This is classified under CWE-20 (Improper Input Validation), indicating that the code does not adequately verify that input meets the security assumptions required for safe cryptographic operations.
Attack Vector
The attack vector for this vulnerability is network-based, allowing remote exploitation. An attacker can target applications that expose pbkdf2-derived functionality through network interfaces. The attack requires some precision in crafting the malicious input (indicated by the attack complexity factors), but does not require authentication or user interaction.
The exploitation flow involves sending specially crafted input to an application using vulnerable pbkdf2 versions. The improper validation in to-buffer.js processes this input incorrectly, resulting in cryptographic outputs that can be predicted or manipulated by the attacker. This enables signature spoofing, where the attacker can generate valid-appearing signatures without the proper cryptographic credentials.
Technical details and verified code examples can be found in the GitHub Security Advisory.
Detection Methods for CVE-2025-6545
Indicators of Compromise
- Unexpected authentication successes with invalid or malformed credentials
- Anomalous input patterns in application logs targeting PBKDF2-related endpoints
- Signature verification passing for data that should fail validation
- Unusual buffer handling errors or edge cases in cryptographic operations
Detection Strategies
- Implement dependency scanning to identify pbkdf2 versions 3.0.10 through 3.1.2 in your codebase
- Monitor application logs for cryptographic operation anomalies or unexpected signature verifications
- Use Software Composition Analysis (SCA) tools to track vulnerable npm dependencies
- Review authentication and signature verification logs for suspicious patterns
Monitoring Recommendations
- Enable detailed logging for all cryptographic operations in applications using pbkdf2
- Set up alerts for unusual authentication patterns that may indicate signature spoofing attempts
- Monitor npm audit reports for known vulnerabilities in the dependency tree
- Track downstream applications that may inherit the vulnerable dependency transitively
How to Mitigate CVE-2025-6545
Immediate Actions Required
- Update pbkdf2 to a patched version that addresses the input validation issue
- Audit applications using pbkdf2 for potential exploitation of this vulnerability
- Review authentication logs for evidence of signature spoofing attempts
- Consider implementing additional input validation at the application layer as defense-in-depth
Patch Information
Security patches for this vulnerability are available through the following commits:
For complete details, refer to the GitHub Security Advisory GHSA-h7cp-r72f-jxh6.
Workarounds
- Implement additional input validation before passing data to pbkdf2 functions
- Consider using alternative PBKDF2 implementations temporarily until the upgrade is completed
- Add application-layer signature verification as a secondary validation step
- Restrict network access to endpoints that utilize pbkdf2-based cryptographic operations
# Update pbkdf2 to the latest patched version
npm update pbkdf2
# Alternatively, specify a minimum version in package.json
npm install pbkdf2@latest
# Audit your project for vulnerable dependencies
npm audit
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
