TDM Digital Signage PC Player 4.1 Insecure File Permissions


Vendor: TDM [Trending Digital Marketing]
Product web page: https://www.tdmsignage.com
                  https://pro.sony/en_NL/products/display-software/tdm-ds1y-tdm-ds3y
Affected version: 4.1.0.4

Summary: With TDM you can do a lot more than just show Digital Signage.
With our Enterprise-Grade software you open the door to Interactive Signage,
Analytics, Proof of Play and a lot more.

Desc: TDM Digital Signage Windows Player suffers from an elevation of
privileges vulnerability which can be used by a simple authenticated
user that can change the executable file with a binary of choice. The
vulnerability exist due to the improper permissions, with the 'M' flag
(Modify) or 'C' flag (Change) for 'Authenticated Users' group.

Tested on: Microsoft Windows 10 Home


Vulnerability discovered by Gjoko 'LiquidWorm' Krstic
                            @zeroscience


Advisory ID: ZSL-2020-5604
Advisory URL: https://www.zeroscience.mk/en/vulnerabilities/ZSL-2020-5604.php

23.09.2020

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C:\>icacls TDMSignage
TDMSignage BUILTIN\Administrators:(I)(OI)(CI)(F)
           NT AUTHORITY\SYSTEM:(I)(OI)(CI)(F)
           BUILTIN\Users:(I)(OI)(CI)(RX)
           NT AUTHORITY\Authenticated Users:(I)(M)              <---------<<<
           NT AUTHORITY\Authenticated Users:(I)(OI)(CI)(IO)(M)  <---------<<<

Successfully processed 1 files; Failed processing 0 files

C:\TDMSignage>dir /b *.exe
Player.exe
unins000.exe

C:\TDMSignage>icacls Player.exe && icacls unins000.exe
Player.exe BUILTIN\Administrators:(I)(F)
           NT AUTHORITY\SYSTEM:(I)(F)
           BUILTIN\Users:(I)(RX)
           NT AUTHORITY\Authenticated Users:(I)(M)              <---------<<<

Successfully processed 1 files; Failed processing 0 files
unins000.exe BUILTIN\Administrators:(I)(F)
             NT AUTHORITY\SYSTEM:(I)(F)
             BUILTIN\Users:(I)(RX)
             NT AUTHORITY\Authenticated Users:(I)(M)            <---------<<<

Successfully processed 1 files; Failed processing 0 files