![]() For example, the name of the database might be known in advance, but not the name of the server. If certain elements of a connection string are known beforehand, they can be stored in a configuration file and retrieved at run time to construct a complete connection string. Initial catalog="AdventureWorks NewValue=Bad"īuilding Connection Strings from Configuration Files data source=(local) Integrated Security=True The output shows that the SqlConnectionStringBuilder handled this correctly by escaping the extra value in double quotation marks instead of appending it to the connection string as a new key/value pair. New () īuilder = "AdventureWorks NewValue=Bad" Ĭonsole.WriteLine(builder.ConnectionString) Dim builder As New īuilder("Initial Catalog") = "AdventureWorks NewValue=Bad"Ĭonsole.WriteLine(builder.ConnectionString) The following example demonstrates how the SqlConnectionStringBuilder handles an inserted extra value for the Initial Catalog setting. In addition, injected values are handled in a safe manner. Checks are performed for valid key/value pairs and an invalid pair throws an exception. Each class maintains a fixed collection of synonyms and can translate from a synonym to the corresponding well-known key name. They provide methods and properties corresponding to the known key/value pairs permitted by each data provider. The connection string builder classes are designed to eliminate guesswork and protect against syntax errors and security vulnerabilities. The connection string is parsed by using a "last one wins" algorithm, and the hostile input is substituted for a legitimate value. For example, an attacker could mount an attack by supplying a semicolon and appending an additional value. If the string is not validated and malicious text or characters not escaped, an attacker can potentially access sensitive data or other resources on the server. Ī connection string injection attack can occur when dynamic string concatenation is used to build connection strings that are based on user input. NET Framework data providers and their associated connection string builder classes. Each data provider includes a strongly typed connection string builder class that inherits from DbConnectionStringBuilder. To address this problem, ADO.NET 2.0 introduced new connection string builders for each. NET Framework data providers supported different syntax for connection string keywords, which made constructing valid connection strings difficult if done manually. In earlier versions of ADO.NET, compile-time checking of connection strings with concatenated string values did not occur, so that at run time, an incorrect keyword generated an ArgumentException.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |