CVE-2021-24171
CWE-434Published: April 5, 2021· Updated: Jun 17, 2026
Official Description
The WooCommerce Upload Files WordPress plugin before 59.4 ran a single sanitization pass to remove blocked extensions such as .php. It was possible to bypass this and upload a file with a PHP extension by embedding a "blocked" extension within another "blocked" extension in the "wcuf_file_name" parameter. It was also possible to perform a double extension attack and upload files to a different location via path traversal using the "wcuf_current_upload_session_id" parameter.
Technical Analysis
CVE-2021-24171 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (4)
Quick Facts
Related CVEs (CWE-434)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-24171 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts