Visa has put out a warning to consumers and businesses about POS system flaws that can jeopardize credit and debit card holder’s security. These POS systems are used by many of America’s largest retail chains.

Visa USA Inc. is warning that two versions of popular software installed at cash registers could be used to steal information from credit and debit cards.

The software, which is used by retailers to help ring up transactions, can be used — sometimes inadvertently — in a way that allows the cash register to store customer data, such as personal-identification numbers used in debit-card transactions. Under card-industry guidelines, retailers aren’t supposed to store that information because it can fall into criminal hands if a computer system is hacked or an unauthorized person gains access to it…

The software company ‘Fujitsu Transaction Solutions Inc.’ denies that its software is being used to steal customer data. Visa has not specified whether the data is being recorded as result of a glitch or from malicious intent.

These reports come several weeks after reports of large amounts of debit card fraud has been traced to OfficeMax stores around the US.

This story can be found at the Wall Street Journal Online: http://online.wsj.com/ but is available by subscription only.