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CVE Record

CVE-2021-4365: Frontend File Manager <= 18.2 - Unauthenticated Stored Cross-Site Scripting

The Frontend File Manager plugin for WordPress is vulnerable to Unauthenticated Stored Cross-Site Scripting in versions up to, and including, 18.2. This is due to lacking authentication protections and santisation all on the wpfm_edit_file_title_desc AJAX action. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

HighCVSS 7.2Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A vulnerable WordPress file-management plugin can let unauthenticated visitors store malicious script content that later runs in another user’s browser. For a business, the main concern is website trust, administrator session exposure, and malicious content served from a public site using Frontend File Manager version 18.2 or earlier.

Executive priority

Treat this as a near-term remediation item for any public WordPress site using the plugin. It is not confirmed exploited in the supplied evidence, but unauthenticated stored XSS can affect customers, site operators, and administrator browser sessions.

Technical view

CVE-2021-4365 is stored XSS in nmedia Frontend File Manager for WordPress through 18.2. The issue is tied to missing authentication protections and insufficient sanitization on the wpfm_edit_file_title_desc AJAX action, allowing unauthenticated script injection that executes when an injected page is viewed. CVSS 3.1 is 7.2 high.

Likely exposure

Exposure is most likely on WordPress sites with the nmedia Frontend File Manager plugin installed at version 18.2 or earlier, especially where the plugin’s file pages are publicly reachable. The supplied affected-product metadata is inconsistent, so confirm installed plugin identity and version directly.

Exploitation context

The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The reported attack conditions are still concerning: network access, no authentication, low complexity, and stored script execution when a user views affected content.

Researcher notes

Focus validation on the wpfm_edit_file_title_desc AJAX action and stored title/description rendering paths. Avoid assuming exploit prevalence. The bundle’s affected-version field appears malformed, while the title and description consistently identify versions up to and including 18.2.

Mitigation direction

  • Inventory WordPress sites for Frontend File Manager plugin usage and version.
  • Apply the vendor or WordPress.org fixed release referenced by the sources.
  • If immediate updating is unavailable, evaluate disabling the plugin until vendor guidance is applied.
  • Review exposed file-management pages for untrusted or unexpected stored content.
  • Monitor WordPress security logs for suspicious unauthenticated AJAX activity.

Validation and detection

  • Confirm whether Frontend File Manager is installed and version is 18.2 or earlier.
  • Check plugin changelog or WordPress.org source changes for the security fix.
  • Review site content for unexpected script-bearing titles or descriptions.
  • Verify unauthenticated users cannot alter file title or description metadata.
  • Run regression checks for plugin file-management workflows after updating.
Prepared
Confidence
medium
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-2021-4365 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
High
CVSS
7.2 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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
7.2CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N3.92.7Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

7.2High
CVSS 3.1 vector shape for CVE-2021-4365Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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
nmediaFrontend File Manager Plugin0unaffected
Weakness

CWE details

CWE-79

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