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.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
None
No data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://gist.github.com/Kr0emer/2560f98edb10b0b34f2438cd63913c47
report@snyk.io
https://github.com/bitwiseshiftleft/sjcl/blob/master/core/ecc.js%23L454-L461
report@snyk.io
https://github.com/bitwiseshiftleft/sjcl/commit/ee307459972442a17beebc29dc331ff…
report@snyk.io
https://security.snyk.io/vuln/SNYK-JS-SJCL-15369617
report@snyk.io