CWE-1204: Generation of Weak Initialization Vector (IV)

Description

The product uses a cryptographic primitive that uses an Initialization Vector (IV), but the product does not generate IVs that are sufficiently unpredictable or unique according to the expected cryptographic requirements for that primitive.

By design, some cryptographic primitives (such as block ciphers) require that IVs must have certain properties for the uniqueness and/or unpredictability of an IV. Primitives may vary in how important these properties are. If these properties are not maintained, e.g. by a bug in the code, then the cryptography may be weakened or broken by attacking the IVs themselves.

Potential Impact

Demonstrative Examples

EVP_CIPHER_CTX ctx;char key[EVP_MAX_KEY_LENGTH];char iv[EVP_MAX_IV_LENGTH];RAND_bytes(key, b);memset(iv,0,EVP_MAX_IV_LENGTH);EVP_EncryptInit(&ctx,EVP_bf_cbc(), key,iv);

public class SymmetricCipherTest {
                              public static void main() {
                              
                              byte[] text ="Secret".getBytes();byte[] iv ={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};KeyGenerator kg = KeyGenerator.getInstance("DES");kg.init(56);SecretKey key = kg.generateKey();Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");IvParameterSpec ips = new IvParameterSpec(iv);cipher.init(Cipher.ENCRYPT_MODE, key, ips);return cipher.doFinal(inpBytes);
                              }
			      }

Mitigations & Prevention

Detection Methods

• Automated Static Analysis High — Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then sea

Real-World CVE Examples

Related Weaknesses