EditorsKit <= 1.40.3 - Authenticated (Administrator+) Arbitrary File Upload
Strategic Overview
- Status
- Patched in 1.40.4
- Affected Plugin
- Gutenberg Block Editor Toolkit – EditorsKit
- Affected Version
<= 1.40.3- CVSS
- 7.2High
- Weakness type
- CWE-434 · Unrestricted Upload of File with Dangerous Type
- CVE
CVE-2023-6635
At a glance
CVE-2023-6635 is a high-severity Unrestricted Upload of File with Dangerous Type vulnerability in the Gutenberg Block Editor Toolkit WordPress plugin, affecting versions <= 1.40.3. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account at Administrator level or above. The issue is fixed in version 1.40.4; sites on affected versions should update now. Disclosed December 2023, reported by István Márton.
Vulnerability Overview
The EditorsKit plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation on the 'import_styles' function in versions up to, and including, 1.40.3. This makes it possible for authenticated attackers with administrator-level capabilities or above, to upload arbitrary files on the affected site's 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 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
Gutenberg Block Editor Toolkit <= 1.40.3 carries this weakness at import_styles, and reaching it takes an account at Administrator level or above. 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 Gutenberg Block Editor Toolkit the fix is 1.40.4: builds <= 1.40.3 are affected, anything from 1.40.4 onward is not.
Remediation
Update to version 1.40.4, or a newer patched version
How does WordSec protect against this?
An attacker needs Administrator access first, so the firewall sees the attempt as traffic from a logged-in account: 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: Gutenberg Block Editor Toolkit 1.40.4 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Alerts
External References
Related records
Other vulnerabilities in Gutenberg Block Editor Toolkit – EditorsKit
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