Improper input validation in Matrix Synapse

CVE-2021-21394

Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.28.0 Synapse is missing input validation of some pa…

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.015 (72.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

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

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-21394?
CVE-2021-21394 is a medium-severity vulnerability in Matrix Synapse, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2021-04-12.
How severe is CVE-2021-21394?
Medium severity. CVSS v3 base score is 5.3 out of 10.