Unsecured WMS dynamic styling sld= parameter affords blind unauthenticated SSRF

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS

• CVE-2023-41339: 0.63% estimated exploitation activity in the next 30 days; percentile 50.37 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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. Details This vulnerability requires: WMS Settings dynamic styling being enabled Security URL checks to be disabled, or to be enabled and allowing file:\\ access Impact This vulnerability can be used to steal user NetNTLMv2 hashes which could be relayed or cracked externally to gain further access. Mitigation 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…

Published by the source

24 Oct 2023, 19:20 UTC

Last modified by the source

6 Mar 2024, 23:57 UTC

Source last checked

26 Oct 2026, 16:29 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-cqpc-x2c6-2gmf

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# Patch Next advisory brief: CVE-2023-41339

Advisory: Unsecured WMS dynamic styling sld= parameter affords blind unauthenticated SSRF
IDs: CVE-2023-41339, GHSA-cqpc-x2c6-2gmf
Record: https://patchnext.com/advisories/cve-2023-41339 (revision 1, source checked 26 Oct 2026, 16:29 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.geoserver.web:gs-web-app 2.23.2, 2.22.5; org.geoserver:gs-wms 2.23.2, 2.22.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.geoserver.web:gs-web-app: affected < 2.22.5; >= 2.23.0, < 2.23.2; fixed in 2.22.5, 2.23.2
- Maven org.geoserver:gs-wms: affected < 2.22.5; >= 2.23.0, < 2.23.2; fixed in 2.22.5, 2.23.2

## Suggested inspection (read-only)
- Maven org.geoserver.web:gs-web-app: check the installed version with your package manager.
- Maven org.geoserver:gs-wms: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.geoserver.web:gs-web-app, org.geoserver:gs-wms.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-cqpc-x2c6-2gmf (GitHub-reviewed advisory GHSA-cqpc-x2c6-2gmf lists affected ranges: Maven org.geoserver:gs-wms >=0 =2.23.0 =0 =2.23.0 <2.23.2)

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