CVE-2021-24760Public exploitNetwork attack vector

Stored XSS via unescaped PDF block markup

Published Oct 18, 2021 · Updated Aug 3, 2024

Stored XSS in Jb Audras PDF Viewer Block for Gutenberg before 1.0.1 allows remote authenticated users to execute script via a crafted block. The plugin preserves unsanitized PDF block markup, allowing an injected onload handler in the block's link URL to reach the rendered page and run in a visitor's browser. Contributor access is sufficient to store the payload; execution requires another user to view the affected content, exposing that user's browser session to script-controlled actions.

CVSS severity5.4
Medium
EPSS probability0.65%
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 Jb Audras PDF Viewer Block for Gutenberg before 1.0.1 allows remote authenticated users to execute script via a crafted block. The plugin preserves unsanitized PDF block markup, allowing an injected onload handler in the block's link URL to reach the rendered page and run in a visitor's browser. Contributor access is sufficient to store the payload; execution requires another user to view the affected content, exposing that user's browser session to script-controlled actions.

The record

CVE
CVE-2021-24760
Published
Oct 18, 2021
Updated
Aug 3, 2024
Vendor
Jb Audras
Product
PDF Viewer Block for Gutenberg
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 18, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0.1 <1.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Jb Audras · PDF Viewer Block for Gutenbergversion=1.0.1 <1.0.1

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NIST NVDAV: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

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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