CVE-2021-21274 – matrix-synapse

Package

Manager: pip
Name: matrix-synapse
Vulnerable Version: >=0.99.0 <1.25.0

Severity

Level: Medium

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

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

EPSS: 0.00584 pctl0.68068

Details

Denial of service attack via .well-known lookups ### Impact A malicious homeserver could redirect requests to their .well-known file to a large file. This can lead to a denial of service attack where homeservers will consume significantly more resources when requesting the .well-known file of a malicious homeserver. This affects any server which accepts federation requests from untrusted servers. ### Patches Issue is resolved by #8950. A bug not affecting the security aspects of this was fixed in #9108. ### Workarounds The `federation_domain_whitelist` setting can be used to restrict the homeservers communicated with over federation.

Metadata

Created: 2021-03-01T19:34:54Z
Modified: 2024-09-30T20:23:54Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/03/GHSA-2hwx-mjrm-v3g8/GHSA-2hwx-mjrm-v3g8.json
CWE IDs: ["CWE-400", "CWE-770"]
Alternative ID: GHSA-2hwx-mjrm-v3g8
Finding: F002
Auto approve: 1