External Media <= 1.0.33 - Authenticated Arbitrary File Upload
Strategic Overview
- Status
- Patched in 1.0.34
- Affected Plugin
- External Media
- Affected Version
< 1.0.34- CVSS
- 8.8High
- Weakness type
- CWE-434 · Unrestricted Upload of File with Dangerous Type
- CVE
CVE-2021-24311
At a glance
CVE-2021-24311 is a high-severity Unrestricted Upload of File with Dangerous Type vulnerability in the External Media WordPress plugin, affecting versions < 1.0.34. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account. The issue is fixed in version 1.0.34; sites on affected versions should update now. Disclosed May 2021, reported by Chloe Chamberland.
Vulnerability Overview
The wp_ajax_upload-remote-file AJAX action of the External Media WordPress plugin before 1.0.34 was vulnerable to arbitrary file uploads via any authenticated users.
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 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 External Media < 1.0.34 takes any authenticated account. 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 External Media the fix is 1.0.34: builds < 1.0.34 are affected, anything from 1.0.34 onward is not.
Remediation
Update to version 1.0.34, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to External Media: 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: External Media 1.0.34 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Alerts
External References
Related records
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