Researchers published a video this week demonstrating how Samsung’s latest entry in the smartphone arena, the Galaxy S5, is vulnerable to a hack that involves lifting and copying fingerprints to trick the phone’s biometric sensor.

Much like the Apple iPhone 5S, the smartphone, which first hit the market last week, boasts a fingerprint scanner as an added layer of security.

Now the same research outfit that was able to hack the iPhone’s 5S’s Touch ID feature last year, Germany’s Security Research Labs (SRLabs), has managed to bypass a similar feature on the Galaxy S5. Like the iPhone hack the Galaxy hack relies on the attackers using a mold of a fingerprint; or in this case a lab-manufactured wood glue replica of a print, to carry out their attack.

In a video posted Tuesday the researchers claim their method allows for “seemingly unlimited authentication attempts without ever requiring a password.”

While this may sound like a pretty farfetched exploit vector – a user would have to have the Finger Scanner set up on this exact brand of phone and an attacker would have to go through the trouble of creating the fingerprint replica – as the folks from SRLabs note, it could have implications for those who use the new fingerprint scan feature on PayPal’s Android app.

That app allows users to transfer funds using their fingerprint as a biometric authenticator, meaning that if an attacker had access to your phone, and one of these fingerprint molds, they’d be able to make purchases and unsolicited money transfers from the account.

In the video the researchers demonstrate how an attacker could wire himself money via PayPal from a person’s debit account. Using the fingerprint replica it takes three swipes for PayPal to recognize the bogus fingerprint, but according to the researcher, attackers could be allowed “multiple attempts to make a successful swipe with this spoof.”

In a statement released by the company this week PayPal downplayed the issue, claiming they were taking SRLabs’ findings seriously but were confident that its app is still “easier and more secure” than using passwords or credit cards. PayPal added that it could simply deactivate cryptographic keys associated with fingerprints on accounts from lost or stolen devices and allow users to make a new one.

The company added that in the unlikely occurrence that one of its users gets duped by an attacker with one of these phony fingerprint scans, it will reimburse any losses they incur.

To use the S5’s fingerprint scanner, the phone requires users to swipe a finger eight times over the home button. The user can then use that fingerprint to lock their screen, verify their Samsung account or authenticate their PayPal account.

A number of critics have been vocal against using fingerprints as a biometric authentication measure for years now. Some of those voices, including researchers from the Chaos Computer Club (CCC) and SRLabs, have pointed out that whenever a fingerprint gets stolen, there’s no way to change it and that it’s easy to lift users’ fingerprints off of items, including their personal devices.

Still though, fingerprint spoofs, known in some circles as ‘fake fingers’ are not easy to produce. CCC hacker Starbug, who was famously the first to break Apple’s TouchID last fall, used a high resolution image of a fingerprint with latex to produce his.

“This demonstrates—again—that fingerprint biometrics is unsuitable as [an] access control method and should be avoided,” the CCC said in September.

Categories: Hacks, Mobile Security, Privacy