Description
Versions of the package sjcl before 1.0.9 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.
Affected products
bitwiseshiftleft: stanford javascript crypto library
References7
- github.com/bitwiseshiftleft/sjcl/commit/ee307459972442a17beebc2… Patch
- gist.github.com/Kr0emer/2560f98edb10b0b34f2438cd63913c47 ExploitMitigationThird Party Advisory
- security.snyk.io/vuln/SNYK-JS-SJCL-15369617 ExploitThird Party Advisory
- gist.github.com/Kr0emer/2560f98edb10b0b34f2438cd63913c47 ExploitMitigationThird Party Advisory
- security.snyk.io/vuln/SNYK-JS-SJCL-15369617 ExploitThird Party Advisory
- github.com/bitwiseshiftleft/sjcl/blob/master/core/ecc.js%23L454… Broken Link
- security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15751243
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 4.0
-
7.7
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 22 · as of 12 November 2026
- CWE
- CWE-347CWE-325
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.