Full Disclosure: AT&T Bizcircle – Persistent Profile Cross Site Scripting Vulnerabilities

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AT&T Bizcircle – Persistent Profile Cross Site Scripting Vulnerabilities

From: Vulnerability Lab
Date: Wed, 11 Jul 2018 15:09:32 +0200

Document Title:
AT&T Bizcircle - Persistent Profile Cross Site Scripting Vulnerabilities

References (Source):

AT&T Reference ID: 1502971499862

Vulnerability Magazine:

Release Date:

Vulnerability Laboratory ID (VL-ID):

Common Vulnerability Scoring System:

Vulnerability Class:
Cross Site Scripting - Persistent

Current Estimated Price:
1.000€ - 2.000€

Product & Service Introduction:
AT&T Inc. is an American multinational conglomerate holding company
headquartered at Whitacre Tower in downtown Dallas, Texas.
AT&T is the world's largest telecommunications company. AT&T is also the
second largest provider of mobile telephone services
and the largest provider of fixed telephone services in the United
States. The company provides broadband subscription
television services through Uverse Tv and DirecTV satellite television.
Combined with AT&T's legacy U-verse service, this
also makes AT&T the largest paid television operator. AT&T is the
second-largest company in Texas, behind ExxonMobil. AT&T is
the 11th largest company in the world. AT&T is the largest
telecommunications company in the world by revenue. As of 2017, it
is also the 21st-largest mobile telecom operator in the world, with
138.8 million mobile customers. AT&T was ranked at #4 on
the 2017 rankings of the world's most valuable brands published by Brand
Finance. Since 2012, AT&T has invested more in the
United States than any other public company.

(Copy of the Homepage: https://en.wikipedia.org/wiki/AT%26T )

Abstract Advisory Information:
The vulnerability laboratory core research team discovered multiple
persistent cross site vulnerabilities in the AT&T Bizcircle online
service web-application.

Vulnerability Disclosure Timeline:
2017-08-16: Researcher Notification & Coordination (Benjamin Kunz Mejri)
2017-08-17: Vendor Notification (AT&T Security Department)
2017-08-25: Vendor Response/Feedback (AT&T Security Department)
2017-11-10: Vendor Fix/Patch (AT&T Service Developer Team)
2018-02-10: Security Acknowledgements  (AT&T Security Department)
2018-07-05: Public Disclosure (Vulnerability Laboratory)

Discovery Status:

Affected Product(s):
AT&T Inc
Product: BizCircle - Online Service (Web-Application) 2017 Q3 - Q4

Exploitation Technique:

Severity Level:

Authentication Type:
Restricted authentication (user/moderator) - User privileges

User Interaction:
Low User Interaction

Disclosure Type:
Bug Bounty Program

Technical Details & Description:
An input validation issue and multiple cross site vulnerabilities has
been discovered in the official AT&T Bizcircle online service
The persistent cross site issue allows remote attackers to inject own
malicious script codes with persistent attack vector to compromise
the frontend or backend of the affected web-application.

The vulnerabilities are located in the `/members/att1759500603/profile/`
section of the content management system. Attackers are able to inject
own malicious script code to the `firstname, lastname, name & groups`
parameters of the `profile` section on update. An attacker could register
and then change the firstname and lastname or shared group to a payload
that is insecure saved into the database management system. The injected
payload provokes a persistent execution of the injected code in the
backend or frontend. Session hijacking, persistent phishing and
backend/frontend exploitation is possible.

The security risk of the persistent xss vulnerabilities are estimated as
medium with a cvss (common vulnerability scoring system) count of 4.6.
Exploitation of the persistent web vulnerability requires a low
privileged web-application user account and only low user interaction.
Successful exploitation of the vulnerability results in persistent
phishing, session hijacking, persistent external redirect
to malicious sources and client-side manipulation of affected or
connected web module context.

Vulnerable Parameter(s):
[+] firstname
[+] lastname
[+] name
[+] groups

Affected Section(s):
[+] Frontend
[+] Backend

Proof of Concept (PoC):
The vulnerabilities can be exploited by remote attackers with low
privileged web-application user account and low user interaction.
For security demonstration or to reproduce the vulnerability follow the
instruction and information below to continue.

Manual steps to reproduce ...
1. Register to the att bizcirlce web-application by usage of the
register function
2. Login to your account and open the profile section
Note: Start a http session tamper in the browser to preview or record
3. Include the payload to the vulnerable marked input fields (firstname,
lastname, name & groups)
4. Save the profile entries by submit of the post method request
5. The execute occurs in the frontend profile section (local), the
groups (shared) and the backend (lists mods/admins the registered user data)
6. Successful reproduce of the persistent cross site vulnerability!

Member ID: att1759500603

PoC: Payload