CVE-2021-21393

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.

CVSS v3.0 6.5 MEDIUM
CVSS v2.0 4.3 MEDIUM

6.5^/10

CVSS v3.0 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

4.3^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:M/Au:N/C:N/I:N/A:P

Exploitability : 8.6 / Impact : 2.9

Access Vector NETWORK

Access Complexity MEDIUM

Authentication NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact PARTIAL

References

Link	Resource
https://github.com/matrix-org/synapse/pull/9321	Patch Third Party Advisory
https://pypi.org/project/matrix-synapse/	Product Third Party Advisory
https://github.com/matrix-org/synapse/pull/9393	Patch Third Party Advisory
https://github.com/matrix-org/synapse/security/advisories/GHSA-jrh7-mhhx-6h88	Patch Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/	Mailing List Third Party Advisory

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Configurations

Configuration 1 (hide)

cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*

Configuration 2 (hide)

cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

Information

Published : 2021-04-12 15:15

Updated : 2021-11-23 14:36

NVD link : CVE-2021-21393

Mitre link : CVE-2021-21393

JSON object : View

CWE

CWE-20

Improper Input Validation

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Products Affected

matrix

synapse

fedoraproject

fedora

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