CVE-2021-34648 json
Ninja Forms <= 3.5.7 Unprotected REST-API to Email Injection
published 2021-09-22 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-21298
- cvss
- 6.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 51%
- public exploits
- 0
- none known
Summary
The Ninja Forms WordPress plugin is vulnerable to arbitrary email sending via the trigger_email_action function found in the ~/includes/Routes/Submissions.php file, in versions up to and including 3.5.7. This allows authenticated attackers to send arbitrary emails from the affected server via the /ninja-forms-submissions/email-action REST API which can be used to socially engineer victims.
Patch / fix
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 19 mo ago
Exploit prediction
0.66% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- wordfence.com https://www.wordfence.com/blog/2021/09/recently-patched-vulnerabilities-in-ninja-forms-plugin-affects-over-1-million-site-owners/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
| NVD | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N |
| NVD | 2.0 | 4.0 | AV:N/AC:L/Au:S/C:N/I:P/A:N |
Affected products
- Saturday Drive Ninja Forms
Classification
- Weakness
- Technology feeds
References
-
plugins.trac.wordpress.org
/browser/ninja-forms/trunk/includes/Routes/Submissions.php?rev=2543837#L155
patch, third-party-advisory
-
wordfence.com
/blog/2021/09/recently-patched-vulnerabilities-in-ninja-forms-plugin-affects-over-1-million-site-owners/
exploit, third-party-advisory
Sources
- CVE List CVE-2021-34648
- NVD CVE-2021-34648
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.