CVE-2021-21394

Published: 12 April 2021

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.

Priority

Medium

CVSS 3 base score: 6.5

Status

Package Release Status
matrix-synapse
Launchpad, Ubuntu, Debian
Upstream
Released (1.28.0-1)
Ubuntu 21.04 (Hirsute Hippo) Needed

Ubuntu 20.10 (Groovy Gorilla) Ignored
(reached end-of-life)
Ubuntu 20.04 LTS (Focal Fossa) Needed

Ubuntu 18.04 LTS (Bionic Beaver) Needed

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist