Adobe Acrobat 9 uses more efficient encryption than previous versions, which makes it easier for attackers to guess a document's password via a brute-force attack.
Weaknesses in this category are related to the design and implementation of data confidentiality and integrity. Frequently these deal with the use of encoding techniques, encryption libraries, and hashing algorithms. The weaknesses in this category could lead to a degradation of the quality data if they are not addressed.