CVE-2021-21393

Description

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.

Risk Information

Base Score

6.5

MODERATE

Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Score

Exploitation Probability

0.548

Associated Vulnerability

Vulnerability	OS Platform
Vulnerabilities CVE-2021-21393,CVE-2021-21394 are fixed in Python-matrix-synapse 1.28.0	Windows
Vulnerabilities CVE-2021-21393,CVE-2021-21394 are fixed in Python-matrix-synapse for linux 1.28.0	Linux

Patch Details

No records found

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234