Google Wallet's PIN has a security vulnerability that leaves it open to a brute force attack, according to research outfit zvelo.
Google Wallet requires users to enter a four-digit PIN to track transaction history and edit card details on its NFC mobile phone.
"Knowing that the PIN can only be a 4-digit numeric value, it dawned on us that a brute-force attack would only require calculating, at most, 10,000 SHA256 hashes. This is trivial even on a platform as limited as a smartphone," says Joshua Rubin, senior engineer, zvelo, in a blog post.
Rubin built an app to test the vulnerability, posting a video of it in action cracking PINs, although only with rooted handsets.
Update: A second more serious flaw has been found by researchers at the Smartphone Champ. An option to clear data and reset payment options on the phone makes it easy for anyone who finds or steals an Android phone to take over the wallet function. It may be no different from losing your physical wallet, but this is a more pressing issue for Google Wallet users. Google says it is aware of the problem and is working on a fix. In the meantime the company is urging users who lose a phone to call a toll free number to disable the pre-paid card function.