What is CVE-2020-6804?

CVE-2020-6804 is a high-severity vulnerability in Mozilla Webthings Gateway, classified under Cross-site Scripting. CVSS score: 8.8/10. Published 2020-02-28.

How severe is CVE-2020-6804?

High severity. CVSS v3 base score is 8.8 out of 10.

XSS in Mozilla Webthings Gateway

CVE-2020-6804

A reflected XSS vulnerability exists within the gateway, allowing an attacker to craft a specialized URL which could steal the user's authentication token. When combined with CVE-2020-6803, an attacker could fully compromise the system.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2020-02-28 · last modified 2026-06-17.

CVSS v3 metric

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

EPSS exploit prediction

EPSS: 0.007 (53.1th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 53.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Mozilla Webthings Gateway — versions 0.3.0, 0.12.0
Mozilla Webthings Gateway

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

github.com/mozilla-iot/gateway/pull/2446 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2020-6804?: CVE-2020-6804 is a high-severity vulnerability in Mozilla Webthings Gateway, classified under Cross-site Scripting. CVSS score: 8.8/10. Published 2020-02-28.
How severe is CVE-2020-6804?: High severity. CVSS v3 base score is 8.8 out of 10.