Language: TypeScript
Label: vulnerable
CWE: CWE-331 \u2014 Insufficient Entropy
The product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.

Code:
  decryptBuffer(key, ciphertext) {
    const bIv = ciphertext.slice(0, NodeCryptography.IV_LENGTH);
    const bCiphertext = ciphertext.slice(NodeCryptography.IV_LENGTH);

    const aes = createDecipheriv(this.algo, key, bIv);

    return Buffer.concat([aes.update(bCiphertext), aes.final()]);
  }