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.
It is possible to use this for "Blind SSRF" on the WMS endpoint to steal NetNTLMv2 hashes via file requests to malicious servers.
This vulnerability requires:
file:\\*
accessThis vulnerability can be used to steal user NetNTLMv2 hashes which could be relayed or cracked externally to gain further access.
The ability to reference an external URL location is defined by the WMS standard GetMap, GetFeatureInfo and GetLegendGraphic operations. These operations are defined by an Industry and International standard and cannot be redefined by the GeoServer application in isolation.
To disable dynamic styling on GeoServer 2.10.3 and GeoServer 2.11.1:
To allow dynamic styling safely on GeoServer 2.22.5 and GeoServer 2.23.2:
^https://styles\.server\.net/cartography/.*$
Use of dynamic styling safely is on by default in GeoServer 2.24.0.
{ "nvd_published_at": "2023-10-25T18:17:30Z", "cwe_ids": [ "CWE-918" ], "severity": "MODERATE", "github_reviewed": true, "github_reviewed_at": "2023-10-24T19:20:34Z" }