CWE-776—Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

Weakness Name

Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

Description

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.

If the DTD contains a large number of nested or recursive entities, this can lead to explosive growth of data when parsed, causing a denial of service.

Common Consequences

Scope:

Availability

Impact:

DoS: Resource Consumption (Other)

Notes:

If parsed, recursive entity references allow the attacker to expand data exponentially, quickly consuming all system resources.

Related Weaknesses

• CWE-405Asymmetric Resource Consumption (Amplification)
• CWE-674Uncontrolled Recursion

Related Alerts

• Exponential Entity Expansion (Billion Laughs Attack)Medium