Auth bypass in Mattermost Server

CVE-2019-20887

An issue was discovered in Mattermost Server before 5.7.1, 5.6.4, 5.5.3, and 4.10.6. It does not honor flags API permissions when deciding whether a user can receive intra-team posts.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.007 (49.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.2% 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-2019-20887: held from 0.007 to 0.007.

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

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-20887?
CVE-2019-20887 is a medium-severity vulnerability in Mattermost Server, classified under Missing Authorization. CVSS score: 4.3/10. Published 2020-06-19.
How severe is CVE-2019-20887?
Medium severity. CVSS v3 base score is 4.3 out of 10.