Security readout for executives and security teams
Plain-English summary
CVE-2021-4368 lets a logged-in WordPress subscriber change Frontend File Manager plugin settings on vulnerable versions up to 18.2. That can allow dangerous upload types and may enable remote code execution when combined with other weaknesses. This is critical for sites allowing user registration or many low-privilege accounts.
Executive priority
Treat this as urgent where affected WordPress sites allow subscriber logins. Prioritize internet-facing sites and customer portals first, because compromise could affect site content, hosted files, and potentially server execution paths.
Technical view
The vulnerable AJAX action, wpfm_save_settings, lacked capability checks and a security nonce. This is CWE-862, missing authorization. The CVSS 3.1 score is 9.9 because exploitation is network-accessible, low-complexity, requires only low privileges, and can affect confidentiality, integrity, and availability.
Likely exposure
Exposure is most likely on WordPress sites running nmedia Frontend File Manager up to and including 18.2, especially where subscriber accounts exist or public registration is enabled.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The attack requires an authenticated low-privilege user and can change upload-related settings; remote code execution is described as possible through other vulnerabilities, not as a standalone guaranteed outcome.
Researcher notes
Evidence supports an authenticated settings-change flaw in the plugin settings AJAX handler. The bundle identifies versions up to 18.2, CWE-862, and CVSS 9.9. It does not provide KEV status, exploitation confirmation, or complete environment-specific exploitability details.
Mitigation direction
- Upgrade Frontend File Manager beyond version 18.2 or to the latest vendor-supported release.
- Disable or remove the plugin if an immediate update is unavailable.
- Review plugin upload settings for dangerous file types or unauthorized changes.
- Restrict public registration and remove unnecessary subscriber accounts.
- Check vendor, Wordfence, and NinTechNet guidance for fixed-version details.
Validation and detection
- Inventory all WordPress sites for Frontend File Manager plugin version and activation status.
- Confirm subscribers cannot change Frontend File Manager settings in staging.
- Review WordPress audit logs for plugin setting changes by low-privilege users.
- Inspect recent uploads for unexpected executable or script-like file types.
- Verify the deployed plugin includes capability and nonce checks for settings saves.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-862: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-4368 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
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.
CVSS vector scores
1 official scoreWe 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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H3.16Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.9CriticalVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/adb1d8b0-b1d6-40df-b591-f1062ee744fb?source=cveCVE reference
- https://blog.nintechnet.com/wordpress-frontend-file-manager-plugin-fixed-multiple-critical-vulnerabilities/CVE reference
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2554359%40nmedia-user-file-uploader&new=2554359%40nmedia-user-file-uploader&sfp_email=&sfph_mail=CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Missing Authorization
Missing Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.