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 Brouillon
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.
Définition
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.
Impact réel
Real-world CVEs caused by CWE-112
Aucune référence CVE publique n'est liée à ce CWE dans le catalogue MITRE pour le moment.
Comment les attaquants l'exploitent
Parcours de l'attaquant étape par étape
- 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.
Exemple de code vulnérable
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) {
...
} Exemple de code sécurisé
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.
Liste de contrôle de prévention
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.
Signaux de détection
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.
Questions fréquentes Qu'est-ce que CWE-112 ?
Quelle est la gravité de CWE-112 ?
Quels langages ou plateformes sont affectés par CWE-112 ?
Comment puis-je prévenir CWE-112 ?
Comment Plexicus détecte et corrige CWE-112 ?
Où puis-je en savoir plus sur CWE-112 ?
Frequently asked questions
Qu'est-ce que 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.
Quelle est la gravité de CWE-112 ?
MITRE n'a pas publié de note de probabilité d'exploitation pour cette faiblesse. Traitez-la comme un impact moyen jusqu'à ce que votre modèle de menace prouve le contraire.
Quels langages ou plateformes sont affectés par CWE-112 ?
MITRE n'a pas spécifié les plateformes affectées pour ce CWE — il peut s'appliquer à la plupart des stacks applicatives.
Comment puis-je prévenir 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.
Comment Plexicus détecte et corrige CWE-112 ?
Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-112 à chaque commit. Lorsqu'une correspondance est trouvée, notre agent Codex Remedium ouvre une PR de correction avec le code corrigé, les tests et un résumé d'une ligne pour le relecteur.
Où puis-je en savoir plus sur CWE-112 ?
MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/112.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.
Ressources
Further reading
- MITRE — CWE-112 officiel 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
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