USAA mobile app gives away personal data; fix released

[David Longenecker <david () 7longeneckers com>]

The USAA Mobile app for Android, prior to version 7.10.1 (released 19
January), contains an information disclosure vulnerability. I have
submitted a CVE-Assign request for this issue but do not yet have a CVE
assigned. The issue is demonstrated with sanitized screen captures at
http://dnlongen.blogspot.com/CVE-2015-USAA

By design, the USAA Mobile app for Android allows users to select whether
to log out immediately upon task-switching (i.e. being interrupted by a
phone call or notification), or to stay logged in for up to 20 minutes.

When "Stay logged in" is enabled however, versions prior to 7.10.1 display
the last-viewed screen *before* prompting the user to log back in. If that
last screen contained sensitive information, such as account numbers and
balances, it becomes possible for one to obtain this information without
authorization. Whether it were 20 minutes later, or a week later, launching
the USAA mobile app would show personal information briefly before blanking
the screen and prompting for a password or PIN.

I would not consider this a severe risk. It cannot be exploited by a remote
attacker - it requires physical access to the mobile device. It also
requires that the attacker is able to log in to the Android device, or that
the device lacks a password-protected lockscreen. I have not found it
possible to take any action without authenticating - the screen is shown
for perhaps a second or two before a login prompt appears. Nonetheless, it
is an unauthenticated information disclosure issue with the app.

With the 7.10.1 version, instead of seeing a screen full of personal
information, the app opens to a benign menu that has no personal
information. Upon choosing a menu option that would show private data, the
user is prompted to log in before any data is shown.

-- 

Regards,
David Longenecker
@dnlongen

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