CVE-2020-26890

published 2020-11-24

CVE-2020-26890: 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…

Priority P3 41 high 7.5 CVSS 3.1

AV N AC L PR N UI N S U C N I N A H

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.

Affected

4 ranges

Vendor	Product	Version range	Fixed in
debian	matrix-synapse	< matrix-synapse 1.20.0-1 (forky)	matrix-synapse 1.20.0-1 (forky)
fedoraproject	fedora	—	—
fedoraproject	fedora	—	—
matrix	synapse	< 1.20.0	1.20.0

CVSS provenance

nvd v3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd v2.0 5.0 MEDIUM AV:N/AC:L/Au:N/C:N/I:N/A:P

osv 7.5 HIGH

vendor_debian 7.5 HIGH

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CWE-20