CVE-2024-42460: Indutny Elliptic Signature Malleability Flaw

CVE-2024-42460 Overview

CVE-2024-42460 is a cryptographic vulnerability affecting the Elliptic package version 6.5.6 for Node.js. The vulnerability stems from ECDSA signature malleability due to a missing validation check for whether the leading bit of the r and s signature components is zero. This oversight allows attackers to create multiple valid signatures for the same message, potentially bypassing signature verification controls in applications that rely on signature uniqueness.

Critical Impact

Applications using the affected Elliptic package may be vulnerable to signature replay attacks or authentication bypasses where signature uniqueness is assumed as a security control.

Affected Products

• Indutny Elliptic version 6.5.6 for Node.js
• Applications and services dependent on the Elliptic npm package for ECDSA cryptographic operations

Discovery Timeline

• August 2, 2024 - CVE-2024-42460 published to NVD
• November 3, 2025 - Last updated in NVD database

Technical Details for CVE-2024-42460

Vulnerability Analysis

The vulnerability exists in the ECDSA signature implementation within the Elliptic package. In properly implemented ECDSA, signatures consist of two integer components (r and s) that must conform to specific formatting requirements to ensure signature uniqueness. The affected version fails to validate that the leading bit of both r and s components is zero when required by DER encoding rules.

This missing check creates a signature malleability issue where an attacker who obtains a valid signature can mathematically derive alternative valid signatures for the same message without possessing the private key. While this does not allow forging signatures for new messages, it undermines security assumptions in systems that treat signature values as unique identifiers or use them in replay protection mechanisms.

Root Cause

The root cause is an improper handling of length with inconsistent values (CWE-130). The Elliptic package's signature verification and generation routines do not properly enforce that the r and s values have their leading bits set to zero when the high bit would otherwise indicate a negative number in DER encoding. This allows for non-canonical signature representations to be accepted as valid.

Attack Vector

The vulnerability is exploitable over the network without requiring authentication or user interaction. An attacker can:

1. Intercept a valid ECDSA signature produced by the vulnerable library
2. Mathematically compute an alternative valid signature for the same message
3. Use the modified signature to bypass systems that assume signature uniqueness

The attack is particularly impactful against:

• Transaction systems that use signature values as unique identifiers
• Replay protection mechanisms relying on signature caching
• Smart contracts or blockchain applications using signature deduplication

The technical details of the signature malleability issue involve the mathematical relationship between valid ECDSA signature representations. When a signature (r, s) is valid, certain transformations can produce alternative valid signatures that pass verification. The fix involves enforcing strict DER encoding requirements to ensure only canonical signature forms are accepted. See the GitHub Pull Request for implementation details.

Detection Methods for CVE-2024-42460

Indicators of Compromise

• Duplicate transactions or operations with mathematically related but different signature values
• Multiple valid signatures for identical message payloads in application logs
• Signature verification successes for non-canonical DER-encoded signatures
• Anomalous patterns in signature r and s component byte lengths

Detection Strategies

• Audit npm dependency trees to identify usage of Elliptic version 6.5.6 using npm ls elliptic or yarn why elliptic
• Implement Software Composition Analysis (SCA) scanning in CI/CD pipelines to flag vulnerable package versions
• Monitor application logs for signature verification patterns that may indicate malleability exploitation
• Use npm audit or similar tools to detect known vulnerabilities in dependencies

Monitoring Recommendations

• Deploy continuous dependency monitoring with alerts for vulnerable Elliptic package versions
• Implement integrity monitoring for cryptographic operations that may be affected by signature malleability
• Review transaction and authentication logs for evidence of signature manipulation attempts
• Establish baseline metrics for signature verification operations to detect anomalous patterns

How to Mitigate CVE-2024-42460

Immediate Actions Required

• Update the Elliptic npm package to a patched version that enforces canonical signature validation
• Audit applications for security controls that assume ECDSA signature uniqueness
• Review and update any signature caching or deduplication mechanisms to account for malleability
• Implement additional signature normalization checks at the application layer if immediate patching is not possible

Patch Information

The vulnerability was addressed through updates to the Elliptic package's signature handling code. Technical details of the fix are available in the GitHub Pull Request #317. Organizations using affected versions should update to the latest patched release. NetApp has also issued a Security Advisory for affected products.

Workarounds

• Implement application-layer signature normalization to convert all signatures to canonical form before processing
• Add secondary validation checks for signature uniqueness that are resistant to malleability
• Consider using alternative cryptographic libraries with strict canonical signature enforcement until patching is complete
• Implement transaction or message-level deduplication that does not rely solely on signature values

# Check for vulnerable Elliptic package versions in your project
npm ls elliptic
# or
yarn why elliptic

# Update Elliptic package to latest version
npm update elliptic
# or
yarn upgrade elliptic

# Audit for known vulnerabilities
npm audit