Security readout for executives and security teams
Plain-English summary
CVE-2021-4338 affects the WordPress plugin 404 to 301 through version 3.0.7. A logged-in user could create or change redirect rules without proper authorization checks. Business risk is moderate: redirects can mislead visitors, support phishing, or alter site behavior, but the sources do not show unauthenticated or actively exploited abuse.
Executive priority
Treat this as a moderate-priority WordPress hygiene issue. Prioritize internet-facing sites with public accounts or many non-admin users, because redirect abuse can damage trust and route visitors to unwanted destinations.
Technical view
The issue is missing capability checks in the plugin's open_redirect and save_redirect functions. Authenticated attackers could view, create, and edit redirections. CVSS 3.1 is 6.4 with network access, low complexity, low privileges, no user interaction, changed scope, and low confidentiality and integrity impact.
Likely exposure
Exposure is likely limited to WordPress sites running 404 to 301 - Redirect, Log and Notify 404 Errors at version 3.0.7 or earlier, especially sites with untrusted subscriber, contributor, customer, or other authenticated users.
Exploitation context
The bundle marks KEV as false, and no provided source states active exploitation. The described attack requires an authenticated account and targets redirect management functions, so risk increases on public-registration, membership, ecommerce, or multi-author WordPress sites.
Researcher notes
The affected behavior is authorization bypass, not a redirect parsing flaw. Keep validation focused on plugin version, capability enforcement around redirect creation and editing, and evidence of unauthorized redirect changes. The provided evidence does not support claims of active exploitation.
Mitigation direction
- Upgrade the plugin to a version newer than 3.0.7, if available.
- Check vendor and WordPress plugin guidance for the confirmed fixed release.
- Restrict or disable untrusted user registration where operationally possible.
- Review existing redirect rules for unauthorized or suspicious destinations.
- Remove the plugin if redirects can be handled safely another way.
Validation and detection
- Inventory WordPress sites for the 404 to 301 plugin and version.
- Confirm no production site runs version 3.0.7 or earlier.
- Review redirect entries for recent unauthorized additions or edits.
- Check WordPress user roles for unnecessary authenticated accounts.
- Verify post-update redirect changes require appropriate administrative capability.
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-284: 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 lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-4338 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
- Medium
- CVSS
- 6.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
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:L/I:L/A:N3.12.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/05d6b27f-b1e5-4bb8-b7db-f8295a5e0d5b?source=cveCVE reference
- https://plugins.trac.wordpress.org/changeset/2546695/404-to-301CVE reference
- https://blog.nintechnet.com/broken-access-control-vulnerability-fixed-in-wordpress-404-to-301-plugin/CVE reference
- https://wpscan.com/vulnerability/9f147107-bc5a-4a01-9979-cd9e16061f12CVE reference
- https://www.acunetix.com/vulnerabilities/web/wordpress-plugin-404-to-301-redirect-log-and-notify-404-errors-security-bypass-3-0-7/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.
Improper Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.