What’s Vulnerable › Vulnerabilities

CVE-2021-33507

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-05-21 · updated 2026-06-17
• Weakness: CWE-79

Description

Zope Products.CMFCore before 2.5.1 and Products.PluggableAuthService before 2.6.2, as used in Plone through 5.2.4 and other products, allow Reflected XSS.

Affected products

• Plone CMS: through 4.3.20; from 5.0 through 5.2.4
• zopefoundation Zope: before 2.5.1 — fixed in 2.5.1

How to fix

Upgrade to a fixed version: zopefoundation Zope 2.5.1. Check the vendor advisory for mitigations.

References

• http://www.openwall.com/lists/oss-security/2021/05/22/1
• https://plone.org/security/hotfix/20210518/reflected-xss-in-various-spots
• http://www.openwall.com/lists/oss-security/2021/05/22/1
• https://plone.org/security/hotfix/20210518/reflected-xss-in-various-spots

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