WooCommerce Help Scout <= 2.9.1 - Arbitrary File Upload to Remote Code Execution
Strategic Overview
- Status
- Patched in 2.9.2
- Affected Plugin
- WooCommerce Help Scout
- Affected Version
<= 2.9.1- CVSS
- 9.8Critical
- Weakness type
- CWE-434 · Unrestricted Upload of File with Dangerous Type
- CVE
CVE-2021-24212
At a glance
CVE-2021-24212 is a critical-severity Unrestricted Upload of File with Dangerous Type vulnerability in the WooCommerce Help Scout WordPress plugin, affecting versions <= 2.9.1. 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 2.9.2; sites on affected versions should update now. Disclosed March 2021, reported by Ville Korhonen / Seravo.
Vulnerability Overview
The WooCommerce Help Scout WordPress plugin before 2.9.1 (https://woocommerce.com/products/woocommerce-help-scout/) allows unauthenticated users to upload any files to the site which by default will end up in wp-content/uploads/hstmp.
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 WooCommerce Help Scout <= 2.9.1 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 WooCommerce Help Scout the fix is 2.9.2: builds <= 2.9.1 are affected, anything from 2.9.2 onward is not.
Remediation
Update to version 2.9.2, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to WooCommerce Help Scout: 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: WooCommerce Help Scout 2.9.2 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Alerts
External References
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