Beware of a "major flaw" in the UPEK Protector Suite software that's been preinstalled on many laptops with built-in UPEK fingerprint readers.

That warning comes from ElcomSoft, a Russian provider of encryption-cracking software.

"After analyzing a number of laptops equipped with UPEK fingerprint readers and running UPEK Protector Suite, we found that your Windows account passwords are stored in [the] Windows registry almost in plain text, barely scrambled but not encrypted," said Olga Koksharova, marketing director at ElcomSoft, in a blog post. As a result, anyone with physical access to a laptop that runs the UPEK Protector Suite can "extract passwords to all user accounts with fingerprint-enabled logon," she said.

[ Is Apple ramping up its security efforts? Read Apple Security Talk Suggests iOS Limits. ]

To mitigate the information security vulnerability, she advised anyone with a laptop that has UPEK Protector Suite installed to ensure that the "Windows logon feature" in the software is disabled for all accounts on the machine, which should then clear all stored passwords. She noted that UPEK's biometric software has been included on devices manufactured by Acer, Asus, Dell, Gateway, Lenovo, MSI, NEC, Samsung, Sony, and Toshiba.

In 2010, $18 million UPEK merged with AuthenTec to create what the companies billed as "the world's largest provider of fingerprint sensors and identity management software, as well as biometric and embedded security solutions." An AuthenTec spokesman didn't immediately respond to emailed request for comment about the security flaw, or about mitigation or upgrade strategies available to anyone who has a device with vulnerable UPEK fingerprint reader software installed. One possibility, however, would appear to be to pay to upgrade to the company's TrueSuite software for Windows.

Koksharova said the UPEK software flaw is quite dangerous, because it undercuts the enhanced security supposedly afforded by having a fingerprint reader. "The common perception is that biometric logon is just as [secure as]--or maybe more secure than--[a] password-based one. While biometric logon could be implemented that way, UPEK apparently failed," she said, owing to developers taking an easy--but insecure--approach to password management. "Storing Windows account passwords in plain text is bad practice. It defeats the entire purpose of enhanced security," she said.

To put the security matter in perspective, Koksharova noted that Windows never stores account passwords on a machine unless the PC is set for "automatic logon." But via in-system warnings as well as support documents, Microsoft urges users to not enable automatic logons, warning that "if you set a computer for automatic logon, anyone who can physically gain access to the computer can also gain access to everything that is on the computer, including any network or networks that the computer is connected to." Microsoft also notes that by enabling automatic logon, "the password is stored in the registry in plain text," which makes it remotely retrievable--for example, by attackers.

Koksharova noted that if an attacker recovered the Windows password, it could be used to decrypt any files stored on the device that had been encrypted with EFS, which is the encrypted file system Windows uses when the "encrypt contents to secure data" file properties checkbox is ticked. "EFS encryption is extremely strong and impossible to break without knowing the original Windows account password," she explained.

Koksharova said that ElcomSoft has informed AuthenTec about the vulnerability, and that in the interests of "public responsibility" will not be publicly releasing full details.

This isn't the first security vulnerability to be discovered that involves UPEK software, which is apparently still sold by AuthenTec. Last year, for example, research firm Vulnerability Laboratory warned that UPEK Protector Suite 2011--and possibly previous versions--were susceptible to a buffer overflow vulnerability. The bug could potentially be exploited by attackers to execute arbitrary code on a machine running the software.

Interestingly, AuthenTec's biometric hardware and software may soon be the property of Apple. Last month, a Securities and Exchange Commission filing by AuthenTec revealed Apple's $356 million bid to acquire the company, as well as the existence of a development agreement between the two companies that dates back to earlier this year. Some industry watchers see the business partnership--and later bid for the company, which is still allowed to receive offers from other potential buyers--as a sign that Apple is preparing to release a more secure iPad and iPhone, especially as the company moves into the mobile payments market with its forthcoming Passbook software.

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