I'm not a bit coin user, but that appears to be an attack on a "remote management" password for the client (it's about "RPC" or "remote procedure call" authentication), not for the wallet.
Wallets use a cryptographic key derivation function, this is against a plain text and configurable password. This would only be an issue if the wallet was loaded into the old version of the software at the time they attacked.
EDIT: I mean exploting this bug: https://github.com/bitcoin/bitcoin/issues/2838