UpdraftPlus < 1.26.5 - Unauthenticated Authentication Bypass via UpdraftCentral udrpc

Description

The plugin does not properly validate the remote communications message format used by its UpdraftCentral feature, allowing the signature verification to be bypassed and the encryption key to be predicted. This makes it possible for unauthenticated attackers to forge arbitrary remote commands and execute them as the connected administrator, ultimately leading to remote code execution.