PROBLEM: A vulnerability has been identified in the Microsoft SQL Server 7.0 encryption used to store administrative login id. PLATFORM: All Microsoft Windows 95, Windows 98, and NT platforms that an SQL DBA (database administrator) could log into with a roaming profile. DAMAGE: Remote and local attackers can decrypt the weakly encrypted file containing the DBA login ID and password. SOLUTION: Follow the procedures given in the bulletin below to prevent passwords from being stored.
VULNERABILITY The risk is medium. A DBA would have to log into a workstation ASSESSMENT: that the attacker has access to, and the login procedure needs to create a weakly encrypted file with the DBA login id and password.
[ Start Internet Security Systems Advisory ] - -----BEGIN PGP SIGNED MESSAGE----- ISS Security Advisory March 14, 2000 Vulnerability in Microsoft SQL Server 7.0 Encryption Used to Store Administrative Login ID Synopsis: Internet Security Systems (ISS) has identified a vulnerability in the encryption used to conceal the password and login ID of a registered SQL Server user in Enterprise Manager for Microsoft SQL Server 7.0. When registering a new SQL Server in the Enterprise Manager or editing the SQL Server registration properties, the login name that will be used by the Enterprise Manager for the connection must be specified. If a SQL Server login name is used instead of a Widows Domain user name and the 'Always prompt for login name and password' checkbox is not set, the login ID and password are weakly encrypted and stored in the registry. When a DBA (database administrator) logs into a workstation with a roaming profile, the login ID and password are stored in a registry key. This information is stored as the file NTUSER.DAT (for Windows NT) or USER.DAT (for Windows 95 or Windows 98) when the user logs off. An attacker can open this file in a text editor to view the DBA login ID and password encrypted. An attacker can reverse this encryption to gain access to the DBA login ID and password. Impact: Remote and local attackers who acquire the system administrator password have full control over the database server software as well as full access to the content and integrity of the database. Affected Versions: Microsoft Enterprise Manager for SQL Server 7.0 is vulnerable. Description: The encryption used to conceal the password and login ID of a registered SQL Server user in Enterprise Manager for SQL Server 7.0 can be reversed. The encryption scheme used is an alphabetic substitution where each Unicode character in the password is XOR'ed with a two byte value according to its position in the string. If the 'Always prompt for login name and password' checkbox is not set when registering a SQL Server, the login ID and password is weakly encrypted and stored in the following registry key: HKEY_CURRENT_USER\SOFTWARE\Microsoft\MSSQLServer\SQLEW\Registered Server X. By design, the HKEY_CURRENT_USER registry hive is meant to be available only to the currently logged on user. That is, when a different Windows NT user logs onto the system, a different copy of the HKEY_CURRENT_USER registry hive is loaded. In practice, the HKEY_CURRENT_USER registry hive is saved locally as the file NTUSER.DAT or USER.DAT when a user logs off. This registry hive can be opened in Notepad and the encrypted login ID and password can be easily located. If the DBA has a roaming profile, the NTUSER.DAT file will be saved on every workstation the DBA logs into. Recommendations: To securely use SQL Server, Microsoft recommends using Windows Integrated Security. In Windows Integrated Security mode passwords are never stored, as your Windows Domain sign-on is used as the security identifier to the database server. If a SQL Server login ID is specified for logging into a server in the Enterprise Manager, Microsoft recommends using the option 'Always prompt for login name and password' to prevent passwords from being stored in the registry. ISS SAFEsuite security assessment software, Database Scanner, contains a security check for this vulnerability and is currently available for customers in the latest version of Database Scanner, 3.0.1. Credits: This vulnerability was discovered by Internet Security Systems (ISS). ISS would like to thank Microsoft for their response and handling of this vulnerability. _____ About Internet Security Systems (ISS) ISS is a leading global provider of security management solutions for e-business. By offering best-of-breed SAFEsuite (tm) security software, industry-leading ePatrol (tm) managed security services, and strategic consulting and education services, ISS is a trusted security provider to its customers, protecting digital assets and ensuring the availability, confidentiality and integrity of computer systems and information critical to e-business success. ISS' lifecycle e-business security management solutions protect more than 5,000 customers including 21 of the 25 largest U.S. commercial banks, 9 of the 10 largest telecommunications companies and over 35 government agencies. Founded in 1994, ISS is headquartered in Atlanta, GA, with additional offices throughout North America and international operations in Asia, Australia, Europe, Latin America and the Middle East. For more information, visit the ISS Web site at www.iss.net or call 888-901-7477. Copyright (c) 2000 by Internet Security Systems, Inc. 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Please send suggestions, updates, and comments to: X-Force (email@example.com) of Internet Security Systems, Inc. - -----BEGIN PGP SIGNATURE----- Version: 2.6.3a Charset: noconv iQCVAwUBOM66ZjRfJiV99eG9AQGpvwQApvXATzDbR07MiRO1pfUh9+A08FU1HdZg ZBbonp/uMfPkDLTRPQ/W/XfYdCMfNlZVoseepvBZ2FlAJtALdAq8n5cFuxynN0m1 fQOsgYIwOjlgNGcnKdRK7hoqBNw4T2JuekwmgecpWzvYMOYXlmtmbCQhnJOx3HU6 nsvR/uJUogk= =HOA2 - -----END PGP SIGNATURE----- [ End Internet Security Systems Advisory ]
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