Cross-site Scripting and Open Redirect in Products.ATContentTypesGHSA-g4c2-ghfg-g5rh
MEDIUMFix: plone/Products.ATContentTypes@fc793f8GHSA-g4c2-ghfg-g5rh is a medium-severity (CVSS 4.3) Cross-site Scripting (XSS) vulnerability in products-atcontenttypes. A fix is available for products-atcontenttypes — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-g4c2-ghfg-g5rh.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-g4c2-ghfg-g5rh by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
products-atcontenttypesReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Plone is vulnerable to reflected cross site scripting and open redirect when an attacker can get a compromised version of the image_view_fullscreen page in a cache, for example in Varnish. The technique is known as cache poisoning. Any later visitor can get redirected when clicking on a link on this page. Usually only anonymous users are affected, but this depends on your cache settings.
Patches
A new version 3.0.6 of Products.ATContentTypes has been released with a fix. This version works on Plone 5.2 (Python 2 only) and will be included in Plone 5.2.7.
Note that the Products.CMFPlone package has the same problem in the 4.3 series.
plone.app.contenttypes has the same problem in all versions, see advisory.
For all unpatched versions of the three packages, you can use the following workaround.
Workaround
Make sure the image_view_fullscreen page is not stored in the cache. In Plone:
- Login as Manager and go to Site Setup.
- Go to the 'Caching' control panel. If this does not exist, or 'Enable caching' is not checked, you should normally not be vulnerable.
- Click on the tab 'Caching operations'.
- Under 'Legacy template mappings' locate the ruleset 'Content item view'.
- From the last column ('Templates') remove 'image_view_fullscreen'.
- Click on Save.
Reporter
This vulnerability was responsibly disclosed to the Plone Security Team by Gustav Hansen, F-Secure Consulting. Thank you!
For more information
If you have any questions or comments about this advisory, email us at [email protected] This is also the correct address to use when you want to report a possible vulnerability. See our security report policy.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | products-atcontenttypes | all versions | 3.0.6pip install --upgrade 'products-atcontenttypes==3.0.6' |
Affected Products
ploneploneDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for products-atcontenttypes, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update products-atcontenttypes to 3.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-g4c2-ghfg-g5rh is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is GHSA-g4c2-ghfg-g5rh in your dependencies?
Find it across PyPI, including transitive dependencies.