Security readout for executives and security teams
Plain-English summary
CVE-2021-24540 is a stored cross-site scripting issue in the Wonder Video Embed WordPress plugin before version 1.8. A Contributor-level user could save malicious script through the plugin shortcode parameters. That script could later run in another user’s browser when affected content is viewed.
Executive priority
Treat as a moderate-priority WordPress hygiene issue. Prioritize sites with many content contributors, untrusted authors, or admin users who regularly review submitted posts.
Technical view
The plugin fails to escape parameters of the `wonderplugin_video` shortcode. Because WordPress Contributors can create content using shortcodes, an authenticated low-privilege user may persist XSS content. The source bundle does not include CVSS scoring, exploit maturity, or detailed fix notes beyond the affected pre-1.8 version range.
Likely exposure
Exposure is limited to WordPress sites that installed Wonder Video Embed before version 1.8 and allow Contributor or higher users to create shortcode content.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. The attack requires authenticated content author access, reducing internet-scale risk but still creating account-abuse and admin-session exposure concerns.
Researcher notes
Evidence supports authenticated stored XSS through shortcode parameter handling. The bundle does not provide payload details, CVSS metrics, proof of exploitation, or complete patch notes. Avoid assuming broader plugin families or unrelated WonderPlugin products are affected.
Mitigation direction
- Inventory WordPress sites for Wonder Video Embed installations.
- Update Wonder Video Embed beyond affected pre-1.8 versions where available.
- Restrict Contributor access on sites using this plugin.
- Review vendor and WPScan guidance for any additional remediation.
- Remove the plugin if it is unused or cannot be updated.
Validation and detection
- Confirm installed plugin version on each WordPress site.
- Search published posts and drafts for `wonderplugin_video` shortcode usage.
- Review Contributor and author accounts for unnecessary access.
- Check web logs and content history for suspicious shortcode edits.
- Verify patched sites no longer run unescaped shortcode parameters.
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-2021-24540 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://wpscan.com/vulnerability/67910e5d-ea93-418b-af81-c50d0e05d213CVE reference · x_refsource_MISC
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.