CVE-2020-26257

Published Dec 9, 2020

Last updated a year ago

Overview

Description
Matrix is an ecosystem for open federated Instant Messaging and VoIP. Synapse is a reference "homeserver" implementation of Matrix. A malicious or poorly-implemented homeserver can inject malformed events into a room by specifying a different room id in the path of a `/send_join`, `/send_leave`, `/invite` or `/exchange_third_party_invite` request. This can lead to a denial of service in which future events will not be correctly sent to other servers over federation. This affects any server which accepts federation requests from untrusted servers. The Matrix Synapse reference implementation before version 1.23.1 the implementation is vulnerable to this injection attack. Issue is fixed in version 1.23.1. As a workaround homeserver administrators could limit access to the federation API to trusted servers (for example via `federation_domain_whitelist`).
Source
security-advisories@github.com
NVD status
Modified

Risk scores

CVSS 3.1

Type
Primary
Base score
6.5
Impact score
3.6
Exploitability score
2.8
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

CVSS 2.0

Type
Primary
Base score
4
Impact score
2.9
Exploitability score
8
Vector string
AV:N/AC:L/Au:S/C:N/I:N/A:P

Weaknesses

nvd@nist.gov
CWE-400
security-advisories@github.com
CWE-400

Social media

Hype score
Not currently trending

Configurations