CVE-2021-32855Public exploitNetwork attack vector

Cross-site scripting via unsanitized pasted HTML

Published Feb 20, 2023 · Updated Mar 10, 2025

Cross-site scripting in B3log Vditor before 3.8.7 allows remote attackers to execute script via malicious HTML pasted by a user. The paste handler reads doc.body.innerHTML into textHTML and forwards it to WYSIWYG processing without sanitizing the clipboard content. Exploitation requires the victim to copy attacker-controlled HTML and paste it into a vulnerable editor, enabling script execution in the page context.

CVSS severity6.1
Medium
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in B3log Vditor before 3.8.7 allows remote attackers to execute script via malicious HTML pasted by a user. The paste handler reads doc.body.innerHTML into textHTML and forwards it to WYSIWYG processing without sanitizing the clipboard content. Exploitation requires the victim to copy attacker-controlled HTML and paste it into a vulnerable editor, enabling script execution in the page context.

The record

CVE
CVE-2021-32855
Published
Feb 20, 2023
Updated
Mar 10, 2025
Vendor
B3log
Product
Vditor
Classifications
CWE-79, T1204.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 20, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 10, 2025Record 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=3.8.7 <3.8.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

B3log · Vditorversion=3.8.7 <3.8.7

Published CVSS scores

6.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.004User Execution: Malicious Copy and Paste

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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