7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5 Medium
CVSS2
Access Vector
Access Complexity
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
0.007 Low
EPSS
Percentile
79.7%
A denial of service attack against Matrix clients can be exploited by sending an event including invalid JSON data to Synapse. Synapse would relay the data to clients which could crash or hang. Impact is long-lasting if the event is made part of the room state.
At a minimum #8106 and #8291 must be applied. #7372 and #8124 include additional checks.
There are no known workarounds.
If an invalid event is accepted by an earlier Synapse it can become part of the room state and will not be fixed by upgrading Synapse. Redacting the invalid event should avoid clients receiving the invalid event.
CPE | Name | Operator | Version |
---|---|---|---|
matrix-synapse | lt | 1.20.0 |
github.com/advisories/GHSA-4mp3-385r-v63f
github.com/matrix-org/synapse/security/advisories/GHSA-4mp3-385r-v63f
lists.fedoraproject.org/archives/list/[email protected]/message/G7YXMMYQP46PYL664JQUXCA3LPBJU7DQ/
lists.fedoraproject.org/archives/list/[email protected]/message/U34DPP4ZLOEDUY2ZCWOHQPU5GA5LYNUQ/
nvd.nist.gov/vuln/detail/CVE-2020-26890
pypi.org/project/matrix-synapse/
7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5 Medium
CVSS2
Access Vector
Access Complexity
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
0.007 Low
EPSS
Percentile
79.7%