CWE-329

Generation of Predictable IV with CBC Mode

The product generates and uses a predictable initialization Vector (IV) with Cipher Block Chaining (CBC) Mode, which causes algorithms to be susceptible to dictionary attacks when they are encrypted under the same key.

Mitigation

Phase: Implementation

Description:

  • NIST recommends two methods of generating unpredictable IVs for CBC mode [REF-1172]. The first is to generate the IV randomly. The second method is to encrypt a nonce with the same key and cipher to be used to encrypt the plaintext. In this case the nonce must be unique but can be predictable, since the block cipher will act as a pseudo random permutation.

No CAPEC attack patterns related to this CWE.

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