The Formidable Form Builder WordPress plugin before 4.09.05 allows to inject certain HTML Tags like <audio>,<video>,<img>,<a> and<button>.This could allow an unauthenticated, remote attacker to exploit a HTML-injection byinjecting a malicous link. The HTML-injection may trick authenticated users to follow the link. If the Link gets clicked, Javascript code can be executed. The vulnerability is due to insufficient sanitization of the "data-frmverify" tag for links in the web-based entry inspection page of affected systems. A successful exploitation incomibantion with CSRF could allow the attacker to perform arbitrary actions on an affected system with the privileges of the user. These actions include stealing the users account by changing their password or allowing attackers to submit their own code through an authenticated user resulting in Remote Code Execution. If an authenticated user who is able to edit Wordpress PHP Code in any kind, clicks the malicious link, PHP code can be edited.
Conclusion & alert: CVE-2021-24884 is rated High Exploit Risk (81.6/100): CVSS Critical severity, with high exploitation likelihood (EPSS 19.16%, 95th percentile). Core evidence: 2 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ | |
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2025-03-30 | 42.43% | 19.16% | -23.27% |
| 2 | 2025-03-29 | 19.16% | 42.43% | +23.27% |
| 3 | 2025-03-28 | — | 19.16% | — |
Full EPSS history (19 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.6 | 3.1 | CRITICAL |
|
2.8 | 6.0 | [email protected] |
| 6.8 | 2.0 | MEDIUM |
|
8.6 | 6.4 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| strategy11 | formidable_form_builder | < 4.09.05 | cpe:2.3:a:strategy11:formidable_form_builder:*:*:*:*:*:wordpress:*:* |
| URL | Tags |
|---|---|
| https://github.com/S1lkys/XSS-in-Formidable-4.09.04/blob/main/XSS-in-Formidable-4.09.04.pdf | Exploit Third Party Advisory |
| https://github.com/Strategy11/formidable-forms/pull/335/files | Patch Third Party Advisory |
| https://wpscan.com/vulnerability/b57dacdd-43c2-48f8-ac1e-eb8306b22533 | Exploit Third Party Advisory |