Lucian Constantin
CSO Senior Writer

URL-spoofing bug in Safari could enable phishing attacks

news
May 19, 20152 mins

Researcher develops code that can trick Safari into showing a different URL in its address bar than the one currently loaded

The latest versions of Safari for Mac OS X and iOS are vulnerable to a URL-spoofing exploit that could allow hackers to launch credible phishing attacks.

The issue was discovered by security researcher David Leo, who published a proof-of-concept exploit for it. Leo’s demonstration consists of a Web page hosted on his domain that, when opened in Safari, causes the browser to display dailymail.co.uk in the address bar.

The ability to control the URL shown by the browser can, for example, be used to easily convince users that they are on a bank’s website when they are actually on a phishing page designed to steal their financial information.

Leo’s proof-of-concept is not perfect and its behavior is somewhat inconsistent. When opened in Safari on iOS, the spoofed URL flickers and sometimes the user can briefly see the real URL.

That’s because the attack code is designed to redirect the browser to the spoofed URL, but before the content is loaded, the code reloads the current page. This happens very fast — every 10 milliseconds — hence the flicker effect.

On Safari on Mac OS X the flickering is much less apparent, so it’s harder to tell that something is amiss.

“While this proof of concept is not perfect, it could definitely be fixed to be used by phishing attacks very easily,” said Manuel Humberto Santander Peláez, a handler with the SANS Internet Storm Center, in a blog post.

The exploit was tested successfully on an up-to-date MacBook Pro running OS X 10.10.3 and Safari 8.0.6, as well as on an iPhone 5S with iOS 8.3.

Lucian Constantin

Lucian Constantin writes about information security, privacy, and data protection for CSO. Before joining CSO in 2019, Lucian was a freelance writer for VICE Motherboard, Security Boulevard, Forbes, and The New Stack. Earlier in his career, he was an information security correspondent for the IDG News Service and Information security news editor for Softpedia.

Before he became a journalist, Lucian worked as a system and network administrator. He enjoys attending security conferences and delving into interesting research papers. He lives and works in Romania.

You can reach him at lucian_constantin@foundryco.com or @lconstantin on X. For encrypted email, his PGP key's fingerprint is: 7A66 4901 5CDA 844E 8C6D 04D5 2BB4 6332 FC52 6D42

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