CVE-2021-4363Public exploitNetwork attack vector

Reflected XSS via printed request parameters

Published Jun 7, 2023 · Updated Apr 8, 2026

Reflected XSS in WP Quick FrontEnd Editor 5.5 and earlier allows remote attackers to execute scripts through crafted save_content_front requests. The save_content_front function passes the complete user-supplied $_REQUEST array to print_r without sanitization or output escaping. No authentication is required, but a user must follow an attacker-controlled link; successful exploitation runs script in that user's browser context.

CVSS severity6.1
Medium
EPSS probability0.74%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in WP Quick FrontEnd Editor 5.5 and earlier allows remote attackers to execute scripts through crafted save_content_front requests. The save_content_front function passes the complete user-supplied $_REQUEST array to print_r without sanitization or output escaping. No authentication is required, but a user must follow an attacker-controlled link; successful exploitation runs script in that user's browser context.

The record

CVE
CVE-2021-4363
Published
Jun 7, 2023
Updated
Apr 8, 2026
Vendor
Labib Ahmed
Product
WP Quick FrontEnd Editor
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 7, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2026Record 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=0 <=5.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Labib Ahmed · WP Quick FrontEnd Editorversion=0 <=5.5

Published CVSS scores

6.1WordfenceCVSS: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.

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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')
T1204.001User Execution: Malicious Link

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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