CWE-776
Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.
Mitigation
Phase: Operation
Description:
- If possible, prohibit the use of DTDs or use an XML parser that limits the expansion of recursive DTD entities.
Mitigation
Phase: Implementation
Description:
- Before parsing XML files with associated DTDs, scan for recursive entity declarations and do not continue parsing potentially explosive content.
CAPEC-197: Exponential Data Expansion
An adversary submits data to a target application which contains nested exponential data expansion to produce excessively large output. Many data format languages allow the definition of macro-like structures that can be used to simplify the creation of complex structures. However, this capability can be abused to create excessive demands on a processor's CPU and memory. A small number of nested expansions can result in an exponential growth in demands on memory.