CVE-2023-41034
DDFFileParser is vulnerable to XXE Attacks
描述
### Impact `DDFFileParser` and `DefaultDDFFileValidator` (and so `ObjectLoader`) are vulnerable to [XXE Attacks](https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing). [DDF file](https://github.com/eclipse-leshan/leshan/wiki/Adding-new-objects#the-lwm2m-model) is a LWM2M format used to store LWM2M object description. Leshan users are impacted only if they parse untrusted DDF files (e.g. if they let external users provide their own model), in that case they MUST upgrade to fixed version. If you parse only trusted DDF file and validate only with trusted xml schema, upgrading is not mandatory. ### Patches This is fixed in **v1.5.0** and **2.0.0-M13**. ### Workarounds No easy way. Eventually writing your own `DDFFileParser`/`DefaultDDFFileValidator` (and so `ObjectLoader`) creating a `DocumentBuilderFactory` with : ```java // For DDFFileParser DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true); factory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true); // Disable DTDs factory.setXIncludeAware(false); // Disable XML Inclusions factory.setExpandEntityReferences(false); // disable expand entity reference nodes // For DefaultDDFFileValidator SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI); factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true); factory.setProperty(XMLConstants.ACCESS_EXTERNAL_DTD, ""); factory.setProperty(XMLConstants.ACCESS_EXTERNAL_SCHEMA, ""); ``` ### References - https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing - https://cheatsheetseries.owasp.org/cheatsheets/XML_External_Entity_Prevention_Cheat_Sheet.html - https://semgrep.dev/docs/cheat-sheets/java-xxe/ - https://community.veracode.com/s/article/Java-Remediation-Guidance-for-XXE
如何修補 CVE-2023-41034
要修補 CVE-2023-41034,請將受影響套件升級到下列已修補版本。
- —升級至 1.5.0 或更新版本
CVE-2023-41034 正在被利用嗎?
低 — EPSS 為 0.1%,目前沒有觀察到大規模利用活動。