Security readout for executives and security teams
Plain-English summary
This is a stored XSS flaw in a WordPress Email Subscriber plugin through version 1.1. A public visitor can submit unsafe subscriber data that is saved and later shown in the admin subscriber list. The business risk is compromise of an administrator’s browser session or misleading admin-side actions if the plugin is present.
Executive priority
Treat this as a targeted WordPress hygiene issue, not a broad emergency. Prioritize sites where this plugin is active on public-facing WordPress instances, because successful abuse could affect administrators who review subscriber records.
Technical view
The kento_email_subscriber_ajax action fails to sanitize, validate, and escape subscribe_email and subscribe_name. Those values are inserted into the database and rendered at /wp-admin/edit.php?post_type=kes_campaign&page=kento_email_subscriber_list_settings, creating stored XSS. The source bundle maps this to CWE-79 and does not provide CVSS details.
Likely exposure
Exposure is likely limited to WordPress sites running the Email Subscriber plugin through 1.1, especially where subscription submissions are publicly reachable. The source bundle does not provide CPEs, install counts, vendor identity, or a confirmed fixed version.
Exploitation context
The source bundle supports unauthenticated stored XSS, but not active exploitation. CISA KEV status is false, and the cited data does not state that attacks are occurring in the wild.
Researcher notes
Evidence identifies the vulnerable action, fields, storage path, and admin render location. It does not name a vendor, CVSS score, exploit-in-the-wild evidence, CPE, or fixed release. Avoid assuming broader Email Subscriber products are affected.
Mitigation direction
- Identify whether the Email Subscriber WordPress plugin is installed and enabled.
- If version is 1.1 or earlier, disable or replace it until vendor guidance is confirmed.
- Check WPScan, CVE, and vendor channels for fixed-version guidance.
- Restrict WordPress admin access to trusted users and protected networks where feasible.
- Review existing subscriber records for suspicious names or email values.
Validation and detection
- Inventory WordPress plugins and confirm the Email Subscriber version.
- Confirm whether public subscription submissions reach kento_email_subscriber_ajax.
- Review the admin subscriber list for untrusted stored subscriber values.
- Check web logs for unusual unauthenticated subscription activity.
- Verify any remediation in staging before returning the plugin to production.
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-2021-24556 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/f050aedc-f79f-4b27-acac-0cdb33b25af8CVE reference · x_refsource_MISC
- https://codevigilant.com/disclosure/2021/wp-plugin-email-subscriber/CVE 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.