Security readout for executives and security teams
Plain-English summary
CVE-2021-4400 affects the Better Search WordPress plugin through version 2.5.2. An attacker could trick a logged-in site administrator into triggering an unwanted settings import or export. The issue is not listed in KEV, and the provided sources do not show active exploitation.
Executive priority
Treat as a routine but real WordPress maintenance issue. It is not currently supported as actively exploited, but affected sites should be updated because successful abuse depends on administrator interaction rather than authentication.
Technical view
The vulnerability is CWE-352 CSRF caused by missing or incorrect nonce validation in bsearch_process_settings_import() and bsearch_process_settings_export(). The CVSS 3.1 score is 4.3. Exploitation requires user interaction by an administrator and can affect plugin settings integrity.
Likely exposure
Exposure is limited to WordPress sites running Better Search versions up to and including 2.5.2. Risk is higher where administrators browse email or external links while authenticated to WordPress.
Exploitation context
Sources describe unauthenticated CSRF via forged requests, but only if an administrator is tricked into an action such as clicking a link. KEV is false, and no provided source confirms active exploitation.
Researcher notes
Focus review on nonce and capability validation around the settings import and export handlers. The provided evidence identifies the vulnerable functions but does not provide a complete exploit record or explicit fixed version in the bundled data.
Mitigation direction
- Inventory WordPress sites for the Better Search plugin and installed version.
- Update Better Search beyond 2.5.2 if vendor guidance confirms a fixed release.
- If no fixed release is available, consider disabling the plugin temporarily.
- Limit WordPress administrator access to trusted users only.
- Warn administrators against opening unsolicited links while logged in.
Validation and detection
- Confirm whether Better Search is installed on each WordPress site.
- Verify installed versions are not 2.5.2 or older.
- Check plugin settings for unexpected import or export changes.
- Review administrative activity around plugin settings changes.
- Confirm vendor release notes or code changes add nonce validation.
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-352: 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.
Open ATT&CK lookupCVE-2021-4400 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
- 4.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/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:N/UI:R/S:U/C:N/I:L/A:N2.81.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/7acbcf74-2bae-412b-bf9d-70287a91deea?source=cveCVE reference
- https://blog.nintechnet.com/25-wordpress-plugins-vulnerable-to-csrf-attacks/CVE reference
- https://blog.nintechnet.com/more-wordpress-plugins-and-themes-vulnerable-to-csrf-attacks/CVE reference
- https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-3/CVE reference
- https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-2/CVE reference
- https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-1/CVE reference
- https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-5/CVE reference
- https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-4/CVE reference
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2473344%40better-search&new=2473344%40better-search&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.
Cross-Site Request Forgery (CSRF)
Cross-Site Request Forgery (CSRF) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.