Cross-site scripting (XSS) vulnerability in the new_fb_sign_button function in nextend-facebook-connect.php in Nextend Facebook Connect plugin before 1.5.6 for WordPress allows remote attackers to inject arbitrary web script or HTML via the redirect_to parameter.
Conclusion & alert: CVE-2015-4413 is rated Exploit Available (50/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.43%). 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 | 6.84% | 0.43% | -6.41% |
| 2 | 2025-03-29 | 0.43% | 6.84% | +6.41% |
| 3 | 2025-03-24 | — | 0.43% | — |
Full EPSS history (8 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 4.3 | 2.0 | MEDIUM |
|
8.6 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| nextendweb | facebook_connect | < 1.5.6 | cpe:2.3:a:nextendweb:facebook_connect:*:*:*:*:*:wordpress:*:* |
| URL | Tags |
|---|---|
| http://packetstormsecurity.com/files/132425/WordPress-Nextend-Facebook-Connect-1.5.4-Cross-Site-Scripting.html | Exploit Third Party Advisory VDB Entry |
| http://seclists.org/fulldisclosure/2015/Jun/70 | Exploit Mailing List Third Party Advisory |
| http://www.securityfocus.com/bid/75391 | Third Party Advisory VDB Entry |
| https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=1178751%40nextend-facebook-connect&old=1060317%40nextend-facebook-connect&sfp_email=&sfph_mail= | Patch Third Party Advisory |
| https://wordpress.org/plugins/nextend-facebook-connect/changelog/ | Release Notes Third Party Advisory |