The application stores sensitive information in cleartext in the registry.
Attackers can read the information by accessing the registry key. Even if the information is encoded in a way that is not human-readable, certain techniques could determine which encoding is being used, then decode the information.
Different people use "cleartext" and "plaintext" to mean the same thing:
the lack of encryption. However, within cryptography, these have more
precise meanings. Plaintext is the information just before it is fed into a
cryptographic algorithm, including already-encrypted text. Cleartext is any
information that is unencrypted, although it might be in an encoded form
that is not easily human-readable (such as base64 encoding).