MariaDB Connector/J is used to connect applications developed in Java to MariaDB and MySQL databases. From 3.0.0 until 3.3.7, 3.4.5, and 3.5.11, the connector assumed result bytes were UTF-8 but guarded only changes to character_set_client. It did not reject non-UTF-8 character_set_results changes and relied on the servers global session_track_system_variables configuration to report character-set changes. A malicious or compromised server, or a machine-in-the-middle attacker, could suppress tracking or change the result charset so application strings differed from the returned bytes, potentially defeating application-side validation or escaping that depended on the decoded values. This issue is fixed in versions 3.3.7, 3.4.5, and 3.5.11.
Weakness
The product uses or specifies an encoding when generating output to a downstream component, but the specified encoding is not the same as the encoding that is expected by the downstream component.
Extended Description
This weakness can cause the downstream component to use a decoding method that produces different data than what the product intended to send. When the wrong encoding is used - even if closely related - the downstream component could decode the data incorrectly. This can have security consequences when the provided boundaries between control and data are inadvertently broken, because the resulting data could introduce control characters or special elements that were not sent by the product. The resulting data could then be used to bypass protection mechanisms such as input validation, and enable injection attacks. While using output encoding is essential for ensuring that communications between components are accurate, the use of the wrong encoding - even if closely related - could cause the downstream component to misinterpret the output. For example, HTML entity encoding is used for elements in the HTML body of a web page. However, a programmer might use entity encoding when generating output for that is used within an attribute of an HTML tag, which could contain functional Javascript that is not affected by the HTML encoding. While web applications have received the most attention for this problem, this weakness could potentially apply to any type of product that uses a communications stream that could support multiple encodings.
Potential Mitigations
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using the ESAPI Encoding control [REF-45] or a similar tool, library, or framework. These will help the programmer encode outputs in a manner less prone to error.
- Note that some template mechanisms provide built-in support for the appropriate encoding.
Related Attack Patterns
References
- https://github.com/mariadb-corporation/mariadb-connector-j/commit/af5e565eb171cfc66ea8e948ddc616abed0c4623
- https://github.com/mariadb-corporation/mariadb-connector-j/commit/d51b968c1b795c73d24e0b3f960205b7bc82d423
- https://github.com/mariadb-corporation/mariadb-connector-j/commit/fdabe74a7df6dce1d6c099f4d0ca1e2acc25919a
- https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.3.7
- https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.4.5
- https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.5.11
- https://github.com/mariadb-corporation/mariadb-connector-j/security/advisories/GHSA-grfq-r75j-rw9x