ShoprLynx version 9.2.3 suffers from an insecure file permissions vulnerability.
34cb6eae09a136075078fd8f17fca5cf
ShaprLynx v9.2.3 Insecure File Permissions
Vendor: Lynx Software Pty Ltd.
Product web page: https://www.sharplynx.com
Affected version: 9.02.0003
Summary: Back Office Software for Sharp POS Terminals. Catering for
the needs of retail and hospitality businesses, SharpLynx has been
developed as a modular software solution with options from simple
program management and sales analysis through to multi-location stock
control.
Desc: SharpLynx 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 'C' flag (Change) for 'Authenticated
Users' group.
Tested on: Microsoft Windows 7 Professional SP1 (EN)
Vulnerability discovered by Gjoko 'LiquidWorm' Krstic
@zeroscience
Advisory ID: ZSL-2018-5456
Advisory URL: https://www.zeroscience.mk/en/vulnerabilities/ZSL-2018-5456.php
27.03.2018
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C:\>cacls "Lynx Software"
C:\Lynx Software BUILTIN\Administrators:(ID)F
BUILTIN\Administrators:(OI)(CI)(IO)(ID)F
NT AUTHORITY\SYSTEM:(ID)F
NT AUTHORITY\SYSTEM:(OI)(CI)(IO)(ID)F
BUILTIN\Users:(OI)(CI)(ID)R
NT AUTHORITY\Authenticated Users:(ID)C
NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(ID)C
C:\Lynx Software\SharpLynx v9>dir *.exe
Volume in drive C has no label.
Volume Serial Number is 54D3-A5E6
Directory of C:\Lynx Software\SharpLynx v9
02/22/2018 02:23 PM 527,840 SL.exe
02/22/2018 02:23 PM 6,747,104 SLE.exe
02/22/2018 02:23 PM 6,747,104 SLED.exe
02/22/2018 02:23 PM 6,747,104 SLER.exe
02/22/2018 02:23 PM 4,932,064 SLU.exe
02/22/2018 02:23 PM 4,932,064 SLUR.exe
07/15/2016 05:58 PM 7,590,288 TeamViewerQS_en.exe
7 File(s) 38,223,568 bytes
0 Dir(s) 2,677,899,264 bytes free
C:\Lynx Software\SharpLynx v9>cacls *.exe
C:\Lynx Software\SharpLynx v9\SL.exe BUILTIN\Administrators:(ID)F
NT AUTHORITY\SYSTEM:(ID)F
BUILTIN\Users:(ID)R
NT AUTHORITY\Authenticated Users:(ID)C
C:\Lynx Software\SharpLynx v9\SLE.exe BUILTIN\Administrators:(ID)F
NT AUTHORITY\SYSTEM:(ID)F
BUILTIN\Users:(ID)R
NT AUTHORITY\Authenticated Users:(ID)C
C:\Lynx Software\SharpLynx v9\SLED.exe BUILTIN\Administrators:(ID)F
NT AUTHORITY\SYSTEM:(ID)F
BUILTIN\Users:(ID)R
NT AUTHORITY\Authenticated Users:(ID)C
C:\Lynx Software\SharpLynx v9\SLER.exe BUILTIN\Administrators:(ID)F
NT AUTHORITY\SYSTEM:(ID)F
BUILTIN\Users:(ID)R
NT AUTHORITY\Authenticated Users:(ID)C
C:\Lynx Software\SharpLynx v9\SLU.exe BUILTIN\Administrators:(ID)F
NT AUTHORITY\SYSTEM:(ID)F
BUILTIN\Users:(ID)R
NT AUTHORITY\Authenticated Users:(ID)C
C:\Lynx Software\SharpLynx v9\SLUR.exe BUILTIN\Administrators:(ID)F
NT AUTHORITY\SYSTEM:(ID)F
BUILTIN\Users:(ID)R
NT AUTHORITY\Authenticated Users:(ID)C
C:\Lynx Software\SharpLynx v9\TeamViewerQS_en.exe BUILTIN\Administrators:(ID)F
NT AUTHORITY\SYSTEM:(ID)F
BUILTIN\Users:(ID)R
NT AUTHORITY\Authenticated Use
rs:(ID)C
C:\Lynx Software\SharpLynx v9>icacls SLE.exe
SLE.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