Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
CWE-112 Base Rascunho
Missing XML Validation
This vulnerability occurs when an application processes XML data from an untrusted source without first validating its structure and content against a defined schema.
Definição
What is CWE-112?
This vulnerability occurs when an application processes XML data from an untrusted source without first validating its structure and content against a defined schema.
When you accept XML without schema validation, you're trusting external data to match your code's expectations. Attackers exploit this gap by sending malformed, oversized, or maliciously crafted XML documents that can trigger parsing errors, consume excessive resources, or enable injection attacks. This fundamentally breaks the security assumption that input will be reasonable and well-formed.
Consistently validating XML against a strict DTD or XML Schema is a critical first line of defense. While SAST tools can detect missing validation patterns, Plexicus uses AI to analyze your code flow and suggest precise fixes—like implementing schema validation libraries or hardening parser configurations—saving hours of manual security review and helping prevent this common oversight across your entire application portfolio.
Impacto no mundo real
Real-world CVEs caused by CWE-112
Ainda não há referências CVE públicas associadas a este CWE no catálogo da MITRE.
Como os atacantes a exploram
Trajeto do atacante passo a passo
- 1
The following code loads and parses an XML file.
- 2
The XML file is loaded without validating it against a known XML Schema or DTD.
- 3
The following code creates a DocumentBuilder object to be used in building an XML document.
- 4
The DocumentBuilder object does not validate an XML document against a schema, making it possible to create an invalid XML document.
Exemplo de código vulnerável
Vulnerable Java
The following code loads and parses an XML file.
```
// Read DOM*
try {
```
...
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setValidating( false );
....
c_dom = factory.newDocumentBuilder().parse( xmlFile );
} catch(Exception ex) {
...
} Exemplo de código seguro
Secure pseudo
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
const safe = validateAndEscape(input);
return executeWithGuards(safe);
} What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Lista de verificação de prevenção
How to prevent CWE-112
- 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.
Sinais de deteção
How to detect CWE-112
CWE-112
Don't catalog this weakness. Prove it's reachable.
Plexicus turns CWE catalogs into evidence: every CWE-pattern is matched against your real code graph, reach is proven on a sandbox clone, and verified findings ship as reviewed PRs.
Perguntas frequentes O que é o CWE-112?
Qual a gravidade do CWE-112?
Que linguagens ou plataformas são afetadas pelo CWE-112?
Como posso prevenir o CWE-112?
Como é que o Plexicus deteta e corrige o CWE-112?
Onde posso saber mais sobre o CWE-112?
Frequently asked questions
O que é o CWE-112?
This vulnerability occurs when an application processes XML data from an untrusted source without first validating its structure and content against a defined schema.
Qual a gravidade do CWE-112?
A MITRE não publicou uma classificação de probabilidade de exploração para esta fraqueza. Trate-a como impacto médio até o seu modelo de ameaças provar o contrário.
Que linguagens ou plataformas são afetadas pelo CWE-112?
A MITRE não especificou as plataformas afetadas por este CWE — pode aplicar-se à maioria das stacks de aplicações.
Como posso prevenir o CWE-112?
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.
Como é que o Plexicus deteta e corrige o CWE-112?
O motor SAST do Plexicus correlaciona a assinatura de fluxo de dados do CWE-112 em cada commit. Quando é encontrada uma correspondência, o nosso agente Codex Remedium abre um PR de correção com o código corrigido, testes e um resumo de uma linha para o revisor.
Onde posso saber mais sobre o CWE-112?
A MITRE publica a definição canónica em https://cwe.mitre.org/data/definitions/112.html. Pode também consultar a documentação da OWASP e do NIST para orientações adjacentes.
Fraquezas relacionadas
Weaknesses related to CWE-112
Recursos
Further reading
- MITRE — CWE-112 oficial https://cwe.mitre.org/data/definitions/112.html
- Seven Pernicious Kingdoms: A Taxonomy of Software Security Errors https://samate.nist.gov/SSATTM_Content/papers/Seven%20Pernicious%20Kingdoms%20-%20Taxonomy%20of%20Sw%20Security%20Errors%20-%20Tsipenyuk%20-%20Chess%20-%20McGraw.pdf
Pronto para validar o que importa?
Pronto para validar o que importa.
O Plexicus é Proof-Driven AppSec: achados validados, compreensão contextual e remediação revisada — ancorada em evidência, escopada com você.