Frontend File Manager < 4.0 & N-Media Post Front-end Form < 1.1 & - Arbitrary File Upload
Strategic Overview
- Status
- Patched in 4.0
- Affected Plugin
- Frontend File Manager Plugin
- Affected Version
< 4.0- CVSS
- 9.8Critical
- Weakness type
- CWE-434 · Unrestricted Upload of File with Dangerous Type
- CVE
CVE-2016-15042
At a glance
CVE-2016-15042 is a critical-severity Unrestricted Upload of File with Dangerous Type vulnerability in the Frontend File Manager Plugin WordPress plugin, affecting versions < 4.0. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 4.0; sites on affected versions should update now. Disclosed July 2016.
Vulnerability Overview
The Frontend File Manager (versions < 4.0), N-Media Post Front-end Form (versions < 1.1) plugins for WordPress are vulnerable to arbitrary file uploads due to missing file type validation via the `nm_filemanager_upload_file` and `nm_postfront_upload_file` AJAX actions. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected sites server which may make remote code execution possible.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.
CWE-434: Unrestricted Upload of File with Dangerous Type
Reaching this weakness in Frontend File Manager Plugin < 4.0 takes a caller who can reach the endpoint. An unrestricted file upload lets a caller store a file whose type or destination the application does not properly constrain.
If an uploaded file lands anywhere the server will execute, the flaw becomes remote code execution and the site should be treated as fully compromised. For Frontend File Manager Plugin the fix is 4.0: builds < 4.0 are affected, anything from 4.0 onward is not.
Remediation
Update to version 4.0, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to Frontend File Manager Plugin: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: Frontend File Manager Plugin 4.0 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Alerts
External References
Related records
Same weakness class
Other vulnerabilities in Frontend File Manager Plugin
- 9.9CVE-2021-4368: Frontend File Manager Settings Change
CVE-2021-4368 - 9.1CVE-2023-5105: Frontend File Manager Plugin Directory Traversal
CVE-2023-5105 - 9.0CVE-2021-4356: Frontend File Manager <= 18.2 Arbitrary File Download
CVE-2021-4356 - 8.8CVE-2022-3126: Frontend File Manager Plugin CSRF to File Upload
CVE-2022-3126 - 8.8Frontend File Manager <= 21.3 CSRF to Plugin Settings Update
- 8.1CVE-2026-8095: Frontend File Manager Plugin Arbitrary File Deletion
CVE-2026-8095 - 8.1CVE-2025-14804: Frontend File Manager <= 23.4 Arbitrary File Deletion
CVE-2025-14804 - 7.5CVE-2026-1280: Frontend File… Unauthenticated Arbitrary File Sharing
CVE-2026-1280
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