CVE-2020-26890

Severity CVSS v4.0:

Pending analysis

Type:

CWE-20 Input Validation

Publication date:

24/11/2020

Last modified:

07/11/2023

Description

Matrix Synapse before 1.20.0 erroneously permits non-standard NaN, Infinity, and -Infinity JSON values in fields of m.room.member events, allowing remote attackers to execute a denial of service attack against the federation and common Matrix clients. If such a malformed event is accepted into the room&#39;s state, the impact is long-lasting and is not fixed by an upgrade to a newer version, requiring the event to be manually redacted instead. Since events are replicated to servers of other room members, the impact is not constrained to the server of the event sender.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.50 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x

7.50

Severity 3.x

HIGH

Vector 2.0

AV:N/AC:L/Au:N/C:N/I:N/A:P CVSS v2.0 Severity and Metrics:

Base Score: 5.00 MEDIUM
Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P

Attack Vector (AV): Network
Attack Complexity (AC): Low
Authentication (Au): None
Confidentiality (C): None
Integrity (I): None
Availability (A): Physical

Base Score 2.0

5.00

Severity 2.0

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:matrix:synapse::::::::		1.20.0 (excluding)
cpe:2.3:o:fedoraproject:fedora:32:::::::*
cpe:2.3:o:fedoraproject:fedora:33:::::::*

To consult the complete list of CPE names with products and versions, see this page

CVE-2020-26890

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools