XSS in Brizy Brizy-Page Builder

CVE-2021-38346

The Brizy Page Builder plugin <= 2.3.11 for WordPress allowed authenticated users to upload executable files to a location of their choice using the brizy_create_block_screenshot AJAX action. The file would be named using the id parameter, which could be prepended with "../" to perform directory traversal, and the file contents were populated via the ibsf parameter, which would be base64-decoded and written to the file. While the plugin added a .jpg extension to all uploaded filenames, a double extension attack was still possible, e.g. a file named shell.php would be saved as shell.php.jpg, and would be executable on a number of common configurations.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.017 (74.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-38346?
CVE-2021-38346 is a high-severity vulnerability in Brizy Brizy-Page Builder, classified under Cross-site Scripting. CVSS score: 8.8/10. Published 2021-10-14.
How severe is CVE-2021-38346?
High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2021-38346 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.