GeoTools has XML External Entity (XXE) Processing Vulnerability in XSD schema handling

Summary

GeoTools Schema class use of Eclipse XSD library to represent schema data structure is vulnerable to XML External Entity (XXE) exploit.

Impact

This impacts whoever exposes XML processing with gt-xsd-core involved in parsing, when the documents carry a reference to an external XML schema. The gt-xsd-core Schemas class is not using the EntityResolver provided by the ParserHandler (if any was configured).

This also impacts users of gt-wfs-ng DataStore where the ENTITY_RESOLVER connection parameter was not being used as intended.

Resolution

GeoTools API change allows EntityResolver to be supplied to the following methods:

Schemas.parse( location, locators, resolvers, uriHandlers, entityResolver);
Schemas.findSchemas(Configuration configuration, EntityResolver entityResolver);

With this API change the gt-wfs-ng WFS DataStore ENTITY_RESOLVER parameter is now used.

Reference

• GHSA-jj54-8f66-c5pc: Describes the impact of the gt-xsd-core vulnerability on the GeoServer WFS protocol, resulting in both Service Side Request Forgery (SSRF) and Out-of-Band (OOB) data exfiltration of local files.

• GHSA-2p76-gc46-5fvc: Describes the impact of the gt-wfs-ng and gt-xsd-core vulnerability on the GeoNetwork WFS Index functionality.