CVE-2021-21392

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 requests to user provided domains were not restricted to external IP addresses when transitional IPv6 addresses were used. Outbound requests to federation, identity servers, when calculating the key validity for third-party invite events, sending push notifications, and generating URL previews are affected. This could cause Synapse to make requests to internal infrastructure on dual-stack networks. See referenced GitHub security advisory for details and workarounds.

Risk Information

Base Score

6.3

MODERATE

Vector

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

EPSS Score

Exploitation Probability

0.2

Associated Vulnerability

Vulnerability	OS Platform
Vulnerabilities CVE-2021-21392 are fixed in Python-matrix-synapse 1.28.0rc1	Windows
Vulnerabilities CVE-2021-21392 are fixed in Python-matrix-synapse for linux 1.28.0rc1	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