Strategic Overview
- Status
- Patched in 1.7.33
- Affected Plugin
- PWA for WP – Progressive Web Apps Made Simple
- Affected Version
<= 1.7.32- CVSS
- 8.8High
- Weakness type
- CWE-434 · Unrestricted Upload of File with Dangerous Type
- CVE
CVE-2021-4354
At a glance
CVE-2021-4354 is a high-severity Unrestricted Upload of File with Dangerous Type vulnerability in the PWA for WP WordPress plugin, affecting versions <= 1.7.32. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). The issue is fixed in version 1.7.33; sites on affected versions should update now. Disclosed July 2021, reported by Jerome Bruandet.
Vulnerability Overview
The PWA for WP & AMP for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the pwaforwp_splashscreen_uploader function in versions up to, and including, 1.7.32. This makes it possible for authenticated 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 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 PWA for WP <= 1.7.32 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 PWA for WP the fix is 1.7.33: builds <= 1.7.32 are affected, anything from 1.7.33 onward is not.
Remediation
Update to version 1.7.33, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to PWA for WP: 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: PWA for WP 1.7.33 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Alerts
External References
Related records
Other vulnerabilities in PWA for WP – Progressive Web Apps Made Simple
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