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Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') and URL Redirection to Untrusted Site ('Open Redirect') in Products.CMFPlone

Moderate
mauritsvanrees published GHSA-8w54-22w9-3g8f Jan 28, 2022

Package

pip Products.CMFPlone (pip)

Affected versions

<5.0.0

Patched versions

5.0.0

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

No patch is available for the Products.CMFPlone 4 series.
Versions 5.0 and higher are not affected, but two other packages used by these versions are affected.

plone.app.contenttypes has the same problem in all versions, see advisory.
In Plone 5.0-5.2, the default Products.ATContentTypes version has the same problem. See advisory.
Plone 5.2.7 and 6.0.0a3 will be released today and will include these fixes.

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 security@plone.org
This is also the correct address to use when you want to report a possible vulnerability.
See our security report policy.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

CVE ID

CVE-2022-23599