Detections
Analytics

SCA: security update for matrix-synapse (GHSA-w9fg-xffh-p362)

medium Tenable Self-Hosted Container Security Plugin ID 419835

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - 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. (CVE-2021-21394)

See Also

https://github.com/advisories/GHSA-w9fg-xffh-p362

Plugin Details

Severity: Medium

ID: 419835

Version: Revision 1.4

Type: Local

Family: SCA Checks

Published: 1/23/2025

Updated: 7/2/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.18

Vendor

Vendor Severity: Medium

CVSS v2

Risk Factor: Medium

Base Score: 4

Temporal Score: 3

Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:P

CVSS Score Source: CVE-2021-21394

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: Medium

Base Score: 6

Threat Score: 2.3

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 4/13/2021

Vulnerability Publication Date: 4/12/2021

Reference Information

CVE: CVE-2021-21394

cwe: CWE-20