Auth bypass in Mattermost Server

CVE-2018-21257

An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for setting a channel header) via the Channel header slash command API.

Vulnerability class: Broken Access Control

EPSS: 0.008 (53.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2018-21257?
CVE-2018-21257 is a medium-severity vulnerability in Mattermost Server, classified under Missing Authorization. CVSS score: 5.3/10. Published 2020-06-19.
How severe is CVE-2018-21257?
Medium severity. CVSS v3 base score is 5.3 out of 10.