Security readout for executives and security teams
Plain-English summary
CVE-2021-4443 is a critical WordPress plugin issue. The provided sources say unauthenticated attackers could create arbitrary PHP files through a vulnerable AJAX action, which can lead to malicious code execution. This is business-critical for exposed WordPress sites running the affected plugin version range.
Executive priority
Prioritize same-day triage for any public WordPress site running the affected plugin. The described impact is full site compromise potential, including data theft, defacement, malware hosting, and service disruption. Where the plugin is absent, risk is not applicable.
Technical view
The bundle describes arbitrary file creation in WordPress Mega Menu / QuadMenu through the compiler_save AJAX action in versions up to and including 2.0.6. It is scored CVSS 9.8 with network access, no authentication, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely on internet-facing WordPress sites with WordPress Mega Menu / QuadMenu installed at version 2.0.6 or earlier. The affected metadata in the bundle is inconsistent, so teams should verify actual installed plugin identity and version against vendor and vulnerability records.
Exploitation context
The provided CVE description supports unauthenticated remote attack potential. The bundle says KEV is false and provides no cited evidence of active exploitation. Treat exploitation status as unconfirmed, not absent, because public WordPress plugin RCE-class flaws are commonly scanned.
Researcher notes
The sources consistently describe arbitrary PHP file creation leading to code execution, but the bundle’s affected-product metadata appears internally inconsistent. Do not rely on CPE data alone. Validate plugin slug, version, and vendor advisory status before closing exposure.
Mitigation direction
- Inventory WordPress sites for the named plugin and installed version.
- Disable or remove affected installations until vendor guidance confirms a safe version.
- Check vendor, Wordfence, CVE, and scanner advisories for current remediation details.
- Review recent filesystem changes for unexpected PHP files.
- Ensure backups and incident response coverage for affected WordPress hosts.
Validation and detection
- Confirm whether the plugin is installed on each WordPress asset.
- Compare installed versions against the described vulnerable range: up to 2.0.6.
- Review webroot and plugin directories for unexpected PHP files.
- Check web and WordPress logs for suspicious access to the named AJAX action.
- Confirm whether compensating controls blocked unauthenticated requests to affected functionality.
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-434: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. 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 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-2021-4443 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
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/04003542-fd62-4587-9834-70e7fe8f08ef?source=cveCVE reference
- https://sh3llcon.org/la-debilidad-de-wordpress/CVE reference
- https://www.acunetix.com/vulnerabilities/web/wordpress-plugin-wordpress-mega-menu-quadmenu-remote-code-execution-2-0-6/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.
Unrestricted Upload of File with Dangerous Type
Unrestricted Upload of File with Dangerous Type represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.