CWE-112: Missing XML Validation

MITRE CWE weakness

Description

The product accepts XML from an untrusted source but does not validate the XML against the proper schema.

Most successful attacks begin with a violation of the programmer's assumptions. By accepting an XML document without validating it against a DTD or XML schema, the programmer leaves a door open for attackers to provide unexpected, unreasonable, or malicious input.

Common consequences

• Integrity: Unexpected State

Mitigations

Architecture and Design — Always validate XML input against a known XML Schema or DTD. It is not possible for an XML parser to validate all aspects of a document's content because a parser cannot understand the complete semantics of the data. However, a parser can do a complete and thorough job of checking the document's structure and therefore guarantee to the code that processes the document that the content is well-formed.

References

• CWE page: https://cwe.mitre.org/data/definitions/112.html
• CWE list: https://cwe.mitre.org/data/index.html