Geonetwork 3.10 through 4.2.0 contains an XML external entity vulnerability in PDF rendering that allows attackers to retrieve arbitrary files from the server. Attackers can exploit the insecure XML parser by crafting a malicious XML document with external entity references to read system files through the baseURL parameter in PDF creation requests.
The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.