GitHub Advisoryadvisory · PyPI

GHSA-5wrh-4jwv-5w78 Open redirect via transitional IPv6 addresses on dual-stack networks

HIGH Published 2021-04-13 Modified 2024-09-30 Official page ↗
Aliases
CVE-2021-21392
Ecosystem
PyPI
Packages
matrix-synapse
Severity
High
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N
Weaknesses
CWE-601
Reviewed
2021-04-12

Affected packages

• PyPI matrix-synapse: < 1.28.0rc1 → fixed in 1.28.0rc1

Description

Impact 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. Patches This issue is fixed by #9240. Workarounds Outbound requests to the following address ranges can be blocked by a firewall, if unused for internal communication between systems: • `::ffff/80` • `::0000/80` (note that this IP range is considered deprecated by the IETF) • `2002::/16` (note that this IP range is considered deprecated by the IETF) References • RFC3056 • RFC4291

Related

Alias · CVE (1)

  • CVE-2021-21392 Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). vulnerability

Weakness · CWE (1)

  • CWE-601 URL Redirection to Untrusted Site weakness

References