CVE-2021-33508Network attack vector

Stored XSS via mishandled owner full name

Published May 21, 2021 · Updated Aug 3, 2024

Stored XSS in Plone 5.2.4 and earlier allows remote authenticated users to execute script in another user's browser via a crafted full name. The ownership tab renders the stored full-name value without sufficient output neutralization when displaying a content item's owner. A user able to change a profile full name must first store the payload, and a separate user must open the affected ownership tab; successful execution can expose or alter browser-accessible data in that user's session.

CVSS severity5.4
Medium
EPSS probability0.63%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Plone 5.2.4 and earlier allows remote authenticated users to execute script in another user's browser via a crafted full name. The ownership tab renders the stored full-name value without sufficient output neutralization when displaying a content item's owner. A user able to change a profile full name must first store the payload, and a separate user must open the affected ownership tab; successful execution can expose or alter browser-accessible data in that user's session.

The record

CVE
CVE-2021-33508
Published
May 21, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.4NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
5.1GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
3.5NIST National Vulnerability DatabaseAV:N/AC:M/Au:S/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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