GeoServer is an open source software server written in Java that allows users to share and edit geospatial data. The WMS specification defines an ``sld=<url>`` parameter for GetMap, GetLegendGraphic and GetFeatureInfo operations for user supplied "dynamic styling". Enabling the use of dynamic styles, without also configuring URL checks, provides the opportunity for Service Side Request Forgery. This vulnerability can be used to steal user NetNTLMv2 hashes which could be relayed or cracked externally to gain further access. This vulnerability has been patched in versions 2.22.5 and 2.23.2.
https://github.com/geoserver/geoserver/security/advisories/GHSA-cqpc-x2c6-2gmf