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CVE Record

CVE-2021-4363: WP Quick FrontEnd Editor <= 5.5 - Reflected Cross-Site Scripting

The WP Quick FrontEnd Editor plugin for WordPress is vulnerable to Reflected Cross-Site Scripting in versions up to, and including, 5.5 due to insufficient input sanitization and output escaping on the 'save_content_front' function that uses print_r on the user-supplied $_REQUEST values . This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

MediumCVSS 6.1Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This vulnerability affects the WP Quick FrontEnd Editor WordPress plugin through version 5.5. An attacker could craft a link that causes malicious script to run in a victim's browser if the victim clicks it. The likely business impact is account misuse, session exposure, or content manipulation within the victim's WordPress context.

Executive priority

Treat this as a moderate-priority WordPress hygiene issue. It is not presented as actively exploited, but unauthenticated reflected XSS can support phishing, session abuse, and administrator-targeted attacks. Prioritize public sites and sites used by privileged editors or administrators.

Technical view

CVE-2021-4363 is a reflected XSS issue, CWE-79, in the save_content_front function. Sources attribute it to insufficient input sanitization and output escaping when user-supplied request values are printed. It is unauthenticated and network reachable, but requires user interaction. CVSS v3.1 is 6.1, medium severity.

Likely exposure

Exposure is likely limited to WordPress sites that installed WP Quick FrontEnd Editor at version 5.5 or earlier. The bundle does not identify other affected products. Sites without this plugin, or with a non-vulnerable maintained version if one exists, are not indicated as exposed.

Exploitation context

The CVE is not listed as CISA KEV in the provided bundle. The sources describe attacker-driven reflected XSS requiring a user to click a crafted link. No source in the bundle provides evidence of active exploitation in the wild.

Researcher notes

Evidence is clear for the vulnerability class, affected plugin, vulnerable range, and CVSS score. The provided bundle does not name a fixed version or provide active exploitation evidence. Avoid assuming patch availability; validate current plugin status against vendor and WordPress plugin records.

Mitigation direction

  • Inventory WordPress sites for WP Quick FrontEnd Editor and record installed versions.
  • Update only to a vendor-confirmed fixed release if one is available.
  • If no fixed maintained release exists, disable or remove the plugin.
  • Reduce exposure by limiting administrative browsing from active WordPress sessions.
  • Monitor vendor, Wordfence, and WordPress plugin guidance for status changes.

Validation and detection

  • Confirm whether WP Quick FrontEnd Editor is installed on each WordPress site.
  • Compare installed plugin versions against the vulnerable range: up to and including 5.5.
  • Review whether the plugin is still required for business operations.
  • Check security logs for suspicious requests involving plugin front-end editing behavior.
  • Verify any remediation by confirming the plugin is updated, disabled, or removed.
Prepared
Confidence
high
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-79: User-session and phishing behavior lookup

Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2021-4363 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.1 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.1CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N2.82.7Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.1Medium
CVSS 3.1 vector shape for CVE-2021-4363Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
labibahmed42WP Quick FrontEnd Editor – WordPress Plugin0unaffected
Weakness

CWE details

CWE-79

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.