https://labs.integrity.pt/articles/google-aosp-email-app-html-injection-2/
1. Vulnerability Properties

*Title: *Google AOSP Email App HTML Injection

*CVE ID: PendingCVSSv3 Base Score: *6.3
(AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L)
*Vendor: *Google
*Products:* AOSP Email App
*Advisory Release Date:*  16 November 2015
*Advisory URL:*
https://labs.integrity.pt/advisories/google-aosp-email-app-html-injection/
*Credits: *Discovery by Cláudio André <ca[at]integrity.pt>
2. Vulnerability Summary

A remote attacker is able to send a crafted email with a payload that
redirects the user to a target url as soon as he opens the email.
3. Technical Details

The vulnerability can be confirmed by sending a HTML email with the
following content:

<meta http-equiv=”refresh” content=”0;URL=’http://www.maliciousurl.com’” />

Exploiting this vulnerability could allow an attacker to redirect a user to
a malicious website, allowing hooking the browser with malicious
JavaScript, launching phishing attacks, explore intent-based URI or browser
vulnerabilities.
4. Vulnerable Versions

   - Confirmed on versions up until 7.0.

5. Solution

   - Users from Android Ice Cream Sandwich (4.0.3) upwards, should migrate
   the accounts from the AOSP Email App to the Gmail App, since the Gmail App
   version 5.0+ is supported.
   - Users with previous Android versions should upgrade to Ice Cream
   Sandwich or above where possible or use a different email client.

6. Vulnerability timeline

   - 16/6/2015 : Issue reported to Google.
   - 26/6/2015 : Issue 178228 created for this vulnerability.
   - 7/7/2015: Asked for feedback.
   - 4/8/2015: Google replied: *After investigation we re-classified this
   issue as Low severity due to the limited risk. The email app in KitKat
   doesn’t execute Javascript, so the potential for exploitation is
low.**Because
   it’s a low severity, we have no plans to backport the fix to KitKat per our
   backport policy posted in the “Notifying Partners” section of
   https://source.android.com/devices/tech/security/overview/updates-resources.html
   <https://source.android.com/devices/tech/security/overview/updates-resources.html>.
   The issue doesn’t apply to later versions of Android.*
   - 4/8/2015: We replied that this issue was not regarding Javascript but
   HTML, and that this issue has big potential for phishing attacks. (We did
   not find any version where Javascript execution was possible)
   - 24/8/2015: Asked for feedback.
   - 22/9/2015: Asked for feedback.
   - 23/10/2015: Google replied that there´s currently no plan to fix this
   issue.
   - 16/11/2015: Advisory released


-- 
Cláudio André
Security Consultant