xbcrypt in Percona XtraBackup before 2.3.6 and 2.4.x before 2.4.5 does not properly set the initialization vector (IV) for encryption, which makes it easier for context-dependent attackers to obtain sensitive information from encrypted backup files via a Chosen-Plaintext attack. NOTE: this vulnerability exists because of an incomplete fix for CVE-2013-6394.

Percona XtraBackup before 2.1.6 uses a constant string for the initialization vector (IV), which makes it easier for local users to defeat cryptographic protection mechanisms and conduct plaintext attacks.