We’ll choose the former to extract the key as LocalMachine encryption uses the Machinekey for encryption and it can be decrypted without impersonating the service account. SMK is encrypted using Windows Data Protection API (DPAPI) and there are two versions of it in the database one encrypted as LocalMachine and the other in the context of CurrentUser (meaning the SQL Server service account here). It is generated automatically the first time it is needed to encrypt another key.” SMK is stored in _encryptions table and it can be identified by the key_id 102. According to “The Service Master Key is the root of the SQL Server encryption hierarchy. To move ahead, access to the Service Master Key (SMK) is required (more information about SMK at ). Time to introduce some MSSQL encryption basics. More details on this can be found on Scott’s blog at. If local administrators don’t have sysadmin privileges you’ll just have to impersonate the MSSQL server account or local SYSTEM account. Sysadmin privileges are needed to start a DAC connection, but as local administrator privileges are needed anyways, that shouldn’t be a problem. The table cannot be accessed using a normal SQL connection, but rather a Dedicated Administrative Connection (DAC) is needed (more information about DAC at ). Specifically, the encrypted password is stored in the “pwdhash” column (even though it’s not a hash). MSSQL stores link server information, including the encrypted password, in table. The remainder of this blog will focus on how that happens. So, if the credentials are encrypted and not hashed, there must be a way for the SQL server to decrypt them prior to use. A one-way hash cannot be used, because the SQL server has to be able to access the cleartext credentials to authenticate to other servers. If SQL server credentials are used, the user account and password are saved to the database encrypted and thus they are stored in a reversible format. When these links are created, they can be configured to use the current security context or static SQL server credentials. Microsoft SQL Server allows users to create links to external data sources, typically to other MSSQL servers. This blog should be interesting to database hackers and admins interested in learning more. From the defensive point of view, this is just another reminder that unnecessary database links, database links with excessive privileges, and the use of SQL server authentication rather than integrated authentication can result in unnecessary risk. From the offensive point of view, this is pretty far into post exploitation as sysadmin privileges are needed on the SQL server and local administrator privileges are needed on the Windows server. And if MSSQL can decrypt them, so can you using the PowerShell script released along with this blog. While MSSQL server hashes local SQL credentials in the database, linked server credentials are stored encrypted. LDAP client tools.Extracting cleartext credentials from critical systems is always fun. With OpenLDAP backend, you can reset it with ldapvi, phpLDAPadmin or other JOcGSlKEz95VeuLGecbL0MwJKy0yWY9foj6UlUVfZ2O2SNkEExU3n42YJLXDbLnu3ghnIRBkwDMsM31q7OI0jY5B/5E=' WHERE backends To generate password hash for new password, please use doveadm command. MD5 is not safe, DO NOT USE IT no matter what reasons you have.SSHA512 is recommended on Linux systems.Time to reset password to prevent mail message leak. To decode the password hash to get plain password, this will give you some In case the SQL/LDAP database was leaked/cracked, cracker still need some time Storing password in plain text is dangerous, so we need to hash the password. Reset password with SQL/LDAP command line Generate password hash for new password Then run script with this file: python3 update_password_in_csv.py new_passwords.csv For example, file new_passwords.csv: 8deNR8IBLycRujDN One mail user (and new password) per line. Reads the user email addresses and NEW passwords from a CSV file. With script shipped in iRedAdmin-Pro: tools/update_password_in_csv.py. If you need to update many users' passwords, another way is resetting passwords Reset passwords for multiple users with a CSV file opt/www/iredadmin): cd /opt/www/iredadmin/tools/ For example, on CentOS 7 (iRedAdmin is installed under IRedAdmin(-Pro) ships script tools/reset_user_password.py to help you reset Reset password with scripts shipped in iRedAdmin(-Pro) Reset password for one user Generate password hash for new password.Reset password with SQL/LDAP command line.Reset passwords for multiple users with a CSV file.Reset password with scripts shipped in iRedAdmin(-Pro).
0 Comments
Leave a Reply. |