The issue arises from insufficient input validation and lack of measures to neutralize instructions in dynamically executed code in the `crypto/rand.Read()` function. This could lead to a predictable shared secret in rare deployment cases where an error is thrown by the `Read()` function. Additionally, the `tkn20` and `blindrsa` components did not check if enough randomness was returned from the user-provided randomness source, typically `crypto/rand.Reader`. If the source does not return the right number of random bytes, the blinding for `blindrsa` is weak, and the integrity of the plaintext is not ensured in `tkn20`.