CVE-2021-21393

Severity CVSS v4.0:
Pending analysis
Type:
CWE-20 Input Validation
Publication date:
12/04/2021
Last modified:
07/11/2023

Description

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 parameters on the endpoints used to confirm third-party identifiers could cause excessive use of disk space and memory leading to resource exhaustion. Note that the groups feature is not part of the Matrix specification and the chosen maximum lengths are arbitrary. Not all clients might abide by them. Refer to referenced GitHub security advisory for additional details including workarounds.

Vulnerable products and versions

CPE From Up to
cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:* 0.24.0 (excluding) 1.28.0 (excluding)
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*