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Improper Verification of Cryptographic Signature

CVE-2026-4258

High
7.7/10

Summary

All versions of the package sjcl are vulnerable to Improper Verification of Cryptographic Signature due to missing point-on-curve validation in "sjcl.ecc.basicKey.publicKey()". An attacker can recover a victim's ECDH private key by sending crafted off-curve public keys and observing ECDH outputs. The "dhJavaEc()" function directly returns the raw x-coordinate of the scalar multiplication result (no hashing), providing a plaintext oracle without requiring any decryption feedback.

  • LOW
  • NETWORK
  • NONE
  • UNCHANGED
  • NONE
  • NONE
  • HIGH
  • NONE

CWE-347 - Improper Verification of Cryptographic Signature

A cryptographic protocol is meant to ensure that services are provided in a secure manner. An application with absent or improper verification of cryptographic signatures allows malicious users to feed false messages to valid users or to disclose sensitive data, subverting the goals of the protocol. This can lead to security failures such as false authentication, account hijacking, and privilege escalation.

References

Advisory Timeline

  • Published