CVE-2021-21392 – matrix-synapse

Package

Manager: pip
Name: matrix-synapse
Vulnerable Version: >=0 <1.28.0rc1

Severity

Level: High

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N

EPSS: 0.002 pctl0.42266

Details

Open redirect via transitional IPv6 addresses on dual-stack networks ### 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](https://tools.ietf.org/html/rfc3056) * [RFC4291](https://tools.ietf.org/html/rfc4291)

Metadata

Created: 2021-04-13T15:13:08Z
Modified: 2024-09-30T20:28:18Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/04/GHSA-5wrh-4jwv-5w78/GHSA-5wrh-4jwv-5w78.json
CWE IDs: ["CWE-601"]
Alternative ID: GHSA-5wrh-4jwv-5w78
Finding: F100
Auto approve: 1