CVE-2020-26890

Published: 24 November 2020

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'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.

Priority

Medium

CVSS 3 base score: 7.5

Status

Package Release Status
matrix-synapse
Launchpad, Ubuntu, Debian
Upstream
Released (1.20.0-1)
Ubuntu 21.04 (Hirsute Hippo) Not vulnerable
(1.23.0-1)
Ubuntu 20.04 LTS (Focal Fossa) Needs triage

Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist