CWE

Not Using a Random IV with CBC Mode

ID: 329		Date: (C)2012-05-14   (M)2022-10-10
Type: weakness		Status: DRAFT
Abstraction Type: Variant

Description

Not using a random initialization Vector (IV) with Cipher Block Chaining (CBC) Mode causes algorithms to be susceptible to dictionary attacks.

Likelihood of Exploit: Medium

Applicable Platforms
Language Class: All

Time Of Introduction

• Architecture and Design
• Implementation

Common Consequences

Scope	Technical Impact	Notes
Confidentiality Other	Read application data Other	If the CBC is not properly initialized, data that is encrypted can be compromised and therefore be read.
Integrity	Modify application data	If the CBC is not properly initialized, encrypted data could be tampered with in transfer.
Access_Control Other	Bypass protection mechanism Other	Cryptographic based authentication systems could be defeated.

Detection Methods
None

Potential Mitigations

Phase	Strategy	Description	Effectiveness	Notes
Implementation		It is important to properly initialize CBC operating block ciphers or their utility is lost.

Relationships

Related CWE	Type	View	Chain
CWE-329 ChildOf CWE-903	Category	CWE-888

Demonstrative Examples   (Details)

1. In the following examples, CBC mode is used when encrypting data:

White Box Definitions
None

Black Box Definitions
None

Taxynomy Mappings

Taxynomy	Id	Name	Fit
CLASP		Not using a random IV with CBC mode

References:

1. Mark Dowd John McDonald Justin Schuh .The Art of Software Security Assessment 1st Edition. Addison Wesley. Section:'Chapter 2, "Initialization Vectors", Page 42.'. Published on 2006.