Create Block Theme <= 1.2.1 - Unauthenticated Arbitrary File Upload
Strategic Overview
- Status
- Patched in 1.2.2
- Affected Plugin
- Create Block Theme
- Affected Version
<= 1.2.1- CVSS
- 9.8Critical
- Weakness type
- CWE-434 · Unrestricted Upload of File with Dangerous Type
- CVE
CVE pending
At a glance
This record tracks a critical-severity Unrestricted Upload of File with Dangerous Type vulnerability in the Create Block Theme WordPress plugin, affecting versions <= 1.2.1. 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 1.2.2; sites on affected versions should update now. Disclosed October 2022.
Vulnerability Overview
The Create Block Theme plugin for WordPress is vulnerable to arbitrary file uploads due to missing authorization via the save_local_fonts_to_theme function among others in versions up to, and including, 1.2.1. 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 Create Block Theme <= 1.2.1 takes no account at all. 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 Create Block Theme the fix is 1.2.2: builds <= 1.2.1 are affected, anything from 1.2.2 onward is not.
Remediation
Update to version 1.2.2, or a newer patched version
How does WordSec protect against this?
Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: 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: Create Block Theme 1.2.2 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Login Security
External References
Related records
Other vulnerabilities in Create Block Theme
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