CWE-827: Improper Control of Document Type Definition | Glexia
CWE-827 (Improper Control of Document Type Definition) weakness overview with consequences, detection methods, mitigations, related CVEs and MITRE ATT&CK context.
Glexia's Take · Automated analysis
CWE-827: Improper Control of Document Type Definition
Improper Control of Document Type Definition represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Confidentiality: Read Files or Directories: If the attacker is able to include a crafted DTD and a default entity resolver is enabled, the attacker may be able to access arbitrary files on the system.
- Availability: DoS: Resource Consumption (CPU) DoS: Resource Consumption (Memory): The DTD may cause the parser to consume excessive CPU cycles or memory using techniques such as nested or recursive entity references (CWE-776).
- Integrity Confidentiality Availability Access Control: Execute Unauthorized Code or Commands Gain Privileges or Assume Identity: The DTD may include arbitrary HTTP requests that the server may execute. This could lead to other attacks leveraging the server's trust relationship with other entities.
Developer Pattern
CWE-827 is the kind of defect developers can usually prevent with explicit validation, safer framework defaults, and tests that exercise hostile input or unsafe state transitions.
Automation confidence
high confidence from CWE-827, 4.20.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Official CWE Definition
CWE-827: Improper Control of Document Type Definition
The product does not restrict a reference to a Document Type Definition (DTD) to the intended control sphere. This might allow attackers to reference arbitrary DTDs, possibly causing the product to expose files, consume excessive system resources, or execute arbitrary http requests on behalf of the attacker.
As DTDs are processed, they might try to read or include files on the machine performing the parsing. If an attacker is able to control the DTD, then the attacker might be able to specify sensitive resources or requests or provide malicious content. For example, the SOAP specification prohibits SOAP messages from containing DTDs.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- Missing validation
- Unsafe defaults
- Insufficient authorization or memory-safety invariant
Remediation
- Use safe APIs
- Centralize the control
- Add regression tests
- Review logs and telemetry for attempted abuse
Detection
- Code review
- SAST
- DAST
- Focused regression tests
Mappings
Related CVEs, CWEs, and ATT&CK context
Related CWEs
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.