Database
Table of content
- MSSQL
MSSQL
MSSQL Azure managed
There is a database gateway
exposed on the common MSSQL
port 1433, but when a connection is made, the connection is redirected to another server on port 1000X
Configuration review
Retrieve server options
To retrieve server options, use the following SQL
command
SELECT * FROM sys.configurations
It will display the status of options such as xp_cmd_shell
or sp_execute_external_script
Transparent data encryption
It is possible to set transparent data encryption. To verify if data encryption is used :
SELECT COUNT(*) FROM sys.dm_database_encryption_keys
To enable data encryption on a specific database:
ALTER DATABASE [database_name] SET ENCRYPTION ON;
Encrypted connections
Use the following SQL
request to check the encryption status of the SQL
connections
SELECT encrypt_option FROM sys.dm_exec_connections
Activate options
xp_cmd_shell
EXEC sp_configure 'show advanced options', 1 ;
GO
RECONFIGURE;
GO
EXEC sp_configure 'xp_cmdshell', 1
GO
RECONFIGURE;
GO
sp_execute_external_script
EXEC sp_configure 'show advanced options', 1 ;
GO
RECONFIGURE;
EXECUTE sp_configure 'external scripts enabled', 1;
GO
RECONFIGURE;
GO
Ole automation procedures
sp_configure 'show advanced options', 1;
GO
RECONFIGURE;
GO
sp_configure 'Ole Automation Procedures', 1;
GO
RECONFIGURE;
GO
Run external script
On Azure MSSQL
it is possible to run external Python or R script with the following command :
EXEC sp_execute_external_script @language = N'R',
@script = N'data.frame(print(system("cmd.exe /C whoami", intern=T)))'
Or, with a python script :
EXECUTE sp_configure 'external scripts enabled', 1;
GO
RECONFIGURE;
GO
EXEC sp_execute_external_script @language = N'Python' , @script = N'import subprocess;
cmd = ["whoami","ipconfig"];
a = "";
for c in cmd:
a += subprocess.check_output(c.split(" "), shell=True).decode()+"\r\n";
a = [elt for elt in a.split("\r\n") if a.strip() != ""];
a = "\n".join(a);
print(a);
'
GO
File system
Enumerate the files
SELECT * FROM sys.dm_os_enumerate_filesystem('C:\', '*');
Read file content
SELECT * FROM OPENROWSET(BULK N'C:\Windows\win.ini', SINGLE_CLOB) AS Contents
Auto audit
This script can be used to auto asset the security level of the database.
I never test it myself
https://www.sqlservercentral.com/articles/sql-server-system-audit-report
Retrieve role information
Security Audit Report
- List all access provisioned to a SQL user or Windows user/group directly
- List all access provisioned to a SQL user or Windows user/group through a database or application role
- List all access provisioned to the public role
Columns Returned:
UserType
: Value will be eitherSQL User
,Windows User
, orWindows Group
. This reflects the type of user/group defined for the SQL Server account.DatabaseUserName
: Name of the associated user as defined in the database user account. The database user may not be the same as the server user.LoginName
: SQL or Windows/Active Directory user account. This could also be an Active Directory group.Role
: The role name. This will be null if the associated permissions to the object are defined at directly on the user account, otherwise this will be the name of the role that the user is a member of.PermissionType
: Type of permissions the user/role has on an object. Examples could includeCONNECT
,EXECUTE
,SELECT
,DELETE
,INSERT
,ALTER
,CONTROL
,TAKE OWNERSHIP
,VIEW
,DEFINITION
, etc. This value may not be populated for all roles. Some built in roles have implicit permission definitions.PermissionState
: Reflects the state of the permission type, examples could includeGRANT
,DENY
, etc. This value may not be populated for all roles. Some built in roles have implicit permission definitions.ObjectType
: Type of object the user/role is assigned permissions on. Examples could includeUSER_TABLE
,SQL_SCALAR_FUNCTION
,SQL_INLINE_TABLE_VALUED_FUNCTION
,SQL_STORED_PROCEDURE
,VIEW
, etc. This value may not be populated for all roles. Some built in roles have implicit permission definitions.Schema
: Name of the schema the object is in.ObjectName
: Name of the object that the user/role is assigned permissions on. This value may not be populated for all roles. Some built in roles have implicit permission definitions.ColumnName
: Name of the column of the object that the user/role is assigned permissions on. This value is only populated if the object is a table, view or a table value function. ```SQL --1) List all access provisioned to a SQL user or Windows user/group directly SELECT [UserType] = CASE princ.[type]
[DatabaseUserName] = princ.[name], [LoginName] = ulogin.[name], [Role] = NULL, [PermissionType] = perm.[permission_name], [PermissionState] = perm.[state_desc], [ObjectType] = CASE perm.[class]WHEN 'S' THEN 'SQL User' WHEN 'U' THEN 'Windows User' WHEN 'G' THEN 'Windows Group' END,
[Schema] = objschem.[name], [ObjectName] = CASE perm.[class]WHEN 1 THEN obj.[type_desc] -- Schema-contained objects ELSE perm.[class_desc] -- Higher-level objects END,
[ColumnName] = col.[name] FROM --Database user sys.database_principals AS princ --Login accounts LEFT JOIN sys.server_principals AS ulogin ON ulogin.[sid] = princ.[sid] --Permissions LEFT JOIN sys.database_permissions AS perm ON perm.[grantee_principal_id] = princ.[principal_id] LEFT JOIN sys.schemas AS permschem ON permschem.[schema_id] = perm.[major_id] LEFT JOIN sys.objects AS obj ON obj.[object_id] = perm.[major_id] LEFT JOIN sys.schemas AS objschem ON objschem.[schema_id] = obj.[schema_id] --Table columns LEFT JOIN sys.columns AS col ON col.[object_id] = perm.[major_id]WHEN 3 THEN permschem.[name] -- Schemas WHEN 4 THEN imp.[name] -- Impersonations ELSE OBJECT_NAME(perm.[major_id]) -- General objects END,
--Impersonations LEFT JOIN sys.database_principals AS imp ON imp.[principal_id] = perm.[major_id] WHERE princ.[type] IN ('S','U','G') -- No need for these system accounts AND princ.[name] NOT IN ('sys', 'INFORMATION_SCHEMA')AND col.[column_id] = perm.[minor_id]
UNION
--2) List all access provisioned to a SQL user or Windows user/group through a database or application role SELECT [UserType] = CASE membprinc.[type] WHEN 'S' THEN 'SQL User' WHEN 'U' THEN 'Windows User' WHEN 'G' THEN 'Windows Group' END, [DatabaseUserName] = membprinc.[name], [LoginName] = ulogin.[name], [Role] = roleprinc.[name], [PermissionType] = perm.[permission_name], [PermissionState] = perm.[state_desc], [ObjectType] = CASE perm.[class] WHEN 1 THEN obj.[type_desc] -- Schema-contained objects ELSE perm.[class_desc] -- Higher-level objects END, [Schema] = objschem.[name], [ObjectName] = CASE perm.[class] WHEN 3 THEN permschem.[name] -- Schemas WHEN 4 THEN imp.[name] -- Impersonations ELSE OBJECT_NAME(perm.[major_id]) -- General objects END, [ColumnName] = col.[name] FROM --Role/member associations sys.database_role_members AS members --Roles JOIN sys.database_principals AS roleprinc ON roleprinc.[principal_id] = members.[role_principal_id] --Role members (database users) JOIN sys.database_principals AS membprinc ON membprinc.[principal_id] = members.[member_principal_id] --Login accounts LEFT JOIN sys.server_principals AS ulogin ON ulogin.[sid] = membprinc.[sid] --Permissions LEFT JOIN sys.database_permissions AS perm ON perm.[grantee_principal_id] = roleprinc.[principal_id] LEFT JOIN sys.schemas AS permschem ON permschem.[schema_id] = perm.[major_id] LEFT JOIN sys.objects AS obj ON obj.[object_id] = perm.[major_id] LEFT JOIN sys.schemas AS objschem ON objschem.[schema_id] = obj.[schema_id] --Table columns LEFT JOIN sys.columns AS col ON col.[object_id] = perm.[major_id] AND col.[column_id] = perm.[minor_id] --Impersonations LEFT JOIN sys.database_principals AS imp ON imp.[principal_id] = perm.[major_id] WHERE membprinc.[type] IN ('S','U','G') -- No need for these system accounts AND membprinc.[name] NOT IN ('sys', 'INFORMATION_SCHEMA')
UNION
--3) List all access provisioned to the public role, which everyone gets by default SELECT [UserType] = '{All Users}', [DatabaseUserName] = '{All Users}', [LoginName] = '{All Users}', [Role] = roleprinc.[name], [PermissionType] = perm.[permission_name], [PermissionState] = perm.[state_desc], [ObjectType] = CASE perm.[class] WHEN 1 THEN obj.[type_desc] -- Schema-contained objects ELSE perm.[class_desc] -- Higher-level objects END, [Schema] = objschem.[name], [ObjectName] = CASE perm.[class] WHEN 3 THEN permschem.[name] -- Schemas WHEN 4 THEN imp.[name] -- Impersonations ELSE OBJECT_NAME(perm.[major_id]) -- General objects END, [ColumnName] = col.[name] FROM --Roles sys.database_principals AS roleprinc --Role permissions LEFT JOIN sys.database_permissions AS perm ON perm.[grantee_principal_id] = roleprinc.[principal_id] LEFT JOIN sys.schemas AS permschem ON permschem.[schema_id] = perm.[major_id] --All objects JOIN sys.objects AS obj ON obj.[object_id] = perm.[major_id] LEFT JOIN sys.schemas AS objschem ON objschem.[schema_id] = obj.[schema_id] --Table columns LEFT JOIN sys.columns AS col ON col.[object_id] = perm.[major_id] AND col.[column_id] = perm.[minor_id] --Impersonations LEFT JOIN sys.database_principals AS imp ON imp.[principal_id] = perm.[major_id] WHERE roleprinc.[type] = 'R' AND roleprinc.[name] = 'public' AND obj.[is_ms_shipped] = 0
ORDER BY [UserType], [DatabaseUserName], [LoginName], [Role], [Schema], [ObjectName], [ColumnName], [PermissionType], [PermissionState], [ObjectType] ```
References
- https://blog.dbdigger.com/enable-and-work-with-xp_cmdshell-in-sql-server-2008-r2/
- https://stackoverflow.com/questions/7048839/sql-server-query-to-find-all-permissions-access-for-all-users-in-a-database
- https://labs.f-secure.com/assets/BlogFiles/mwri-a-penetration-testers-guide-to-the-azure-cloud-v1.2.pdf
- https://www.netspi.com/blog/technical/adversary-simulation/decrypting-mssql-credential-passwords/