XSS in Flatpress

CVE-2024-4023

A stored cross-site scripting (XSS) vulnerability exists in flatpressblog/flatpress version 1.3. When a user uploads a file with a `.xsig` extension and directly accesses this file, the server responds with a Content-type of application/octet-stream, leading to the file being processed as an HTML file. This allows an attacker to execute arbitrary JavaScript code, which can be used to steal user cookies, perform HTTP requests, and access content of the same origin.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H.

EPSS exploit prediction

EPSS: 0.008 (54.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 54.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2024-4023: held from 0.008 to 0.008.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2024-4023?
CVE-2024-4023 is a high-severity vulnerability in Flatpress, classified under Cross-site Scripting. CVSS score: 8.1/10. Published 2025-03-20.
How severe is CVE-2024-4023?
High severity. CVSS v3 base score is 8.1 out of 10.