Security readout for executives and security teams
Plain-English summary
A WordPress page builder plugin can let logged-in contributors store malicious script in content. That script runs when someone views the affected page, potentially exposing session data or altering page behavior. The issue requires an account with Contributor-level access or higher, which limits but does not remove business risk.
Executive priority
Treat as a moderate-priority web risk. Prioritize sites with many contributors, external authors, or sensitive admin sessions. It is not KEV-listed in the provided sources, but stored XSS can still create reputational and account-security impact.
Technical view
Essential Blocks for Gutenberg is vulnerable to stored XSS through the data-marker parameter in versions up to and including 5.2.3. The cause is insufficient input sanitization and output escaping. CVSS 3.1 is 6.4, with low privilege required and changed scope.
Likely exposure
Exposure is likely limited to WordPress sites running Essential Blocks <= 5.2.3 where contributors, authors, editors, or admins can create or modify content.
Exploitation context
The source bundle does not show KEV listing or active exploitation. Exploitation requires authenticated Contributor-level access or higher. Successful abuse stores script in a page, which executes when a user accesses that injected page.
Researcher notes
Evidence supports authenticated stored XSS in a specific parameter and affected range through 5.2.3. The provided bundle references a WordPress.org changeset, but does not explicitly name a fixed release. Avoid assuming exploit activity or additional affected products without vendor confirmation.
Mitigation direction
- Identify all WordPress sites using Essential Blocks.
- Upgrade affected plugin versions beyond 5.2.3 when vendor guidance confirms availability.
- Review and restrict Contributor-level access on affected sites.
- Remove or review untrusted content created by contributor accounts.
- Check vendor and Wordfence guidance for current remediation details.
Validation and detection
- Inventory installed Essential Blocks versions across WordPress sites.
- Confirm whether any site runs version 5.2.3 or earlier.
- Review contributor-created pages for unexpected embedded script behavior.
- Check WordPress audit logs for suspicious content edits.
- Verify remediation against the WordPress.org changeset and vendor guidance.
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-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.
Open ATT&CK lookupCVE-2024-13803 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
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 Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.