what you don't know can hurt you

DropBox iOS / Android App File Theft

DropBox iOS / Android App File Theft
Posted Oct 20, 2012
Authored by Roi Saltzman

DropBox version 1.4.6 on iOS, 2.0.1 on Android, and Google Drive version 1.0.1 on iOS suffer from a file theft vulnerability due to allowing arbitrary javascript to be executed inside of the privileged file zone.

tags | advisory, arbitrary, javascript
systems | apple
MD5 | aee44986c95172241f9bcc6c7ebf9aa9

DropBox iOS / Android App File Theft

Change Mirror Download
1 Introduction
================================================
Recently, I discovered a security vulnerability in several file-sharing apps:
DropBox iOS app, DropBox Android app and Google Drive iOS app.

Exploiting this vulnerability, an attacker could steal arbitrary files
from a DropBox / Google Drive user by tricking him into viewing a malicious
HTML file inside the mobile app.

The full blog post, including the advisories, can be found at:
http://bit.ly/R6nNee


2 Vulnerability
================================================
A significant feature of file-sharing apps is allowing a user to view either
his files or files shared with him. The apps achieve this by using an embedded
browser (using the UIWebView/WebView classes in iOS/Android respectively)
to display the contents of these files. Amongst numerous file types,
these apps allow the user to view HTML files in a rendered format.
To do so, these apps use an embedded browser window to render the
locally stored HTML file.

The method in which these apps render an HTML file has two side effects:
1. JavaScript code contained in the HTML file is automatically executed
2. The HTML content is loaded in a privileged file zone

Execution of malicious JavaScript code allows an attacker to steal potentially
valuable information from the DOM of the embedded browser, an attack dubbed
"Cross-Application Scripting" (XAS). However, because these apps load the HTML
file from a privileged zone such as
"file:///var/mobile/Applications/APP_UUID/…/maliciousfile.html"
(in iOS), the malicious JavaScript can also access the file system with the
same permissions as the app.


3 Impact
================================================
By exploiting this vulnerability, an attacker could read and retrieve files
that the apps themselves can access. For instance, previously cached files,
application configuration files, the device's address book, etc.
Furthermore, additional access can be achieved pending on the OS:

- In iOS, read access to the user's DropBox unencrypted credentials
(../Library/Preferences/com.getdropbox.Dropbox.plist). Having access to
the user's credentials allows the attacker to retrieve arbitrary files from
the user's account as well as to persist the attack by modifying other
HTML files.

- In Android, read access to the device's SD card is possible if the app
has permission to do so.

Once the HTML file is rendered, the JavaScript code executes immediately.
However, when the user has finished viewing the file (e.g. pressed the
Home button),
code execution is suspended until the user views the file again.


4 Vulnerable versions
================================================
DropBox:
- Version 1.4.6 (iOS)
- Version 2.0.1 (Android)
Google Drive:
- Version 1.0.1 (iOS)


5 Credit
================================================
Discovered by Roi Saltzman <roisaltzman () [google's mail server] com>


6 Acknowledgments
================================================
I'd like to thank the DropBox / Google security response teams for
the quick fixes!

Comments

RSS Feed Subscribe to this comment feed

No comments yet, be the first!

Login or Register to post a comment

File Archive:

August 2019

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Aug 1st
    10 Files
  • 2
    Aug 2nd
    8 Files
  • 3
    Aug 3rd
    2 Files
  • 4
    Aug 4th
    1 Files
  • 5
    Aug 5th
    15 Files
  • 6
    Aug 6th
    79 Files
  • 7
    Aug 7th
    16 Files
  • 8
    Aug 8th
    10 Files
  • 9
    Aug 9th
    10 Files
  • 10
    Aug 10th
    0 Files
  • 11
    Aug 11th
    6 Files
  • 12
    Aug 12th
    26 Files
  • 13
    Aug 13th
    15 Files
  • 14
    Aug 14th
    19 Files
  • 15
    Aug 15th
    52 Files
  • 16
    Aug 16th
    11 Files
  • 17
    Aug 17th
    1 Files
  • 18
    Aug 18th
    1 Files
  • 19
    Aug 19th
    18 Files
  • 20
    Aug 20th
    0 Files
  • 21
    Aug 21st
    0 Files
  • 22
    Aug 22nd
    0 Files
  • 23
    Aug 23rd
    0 Files
  • 24
    Aug 24th
    0 Files
  • 25
    Aug 25th
    0 Files
  • 26
    Aug 26th
    0 Files
  • 27
    Aug 27th
    0 Files
  • 28
    Aug 28th
    0 Files
  • 29
    Aug 29th
    0 Files
  • 30
    Aug 30th
    0 Files
  • 31
    Aug 31st
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2019 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close