{"document":{"aggregate_severity":{"namespace":"https://www.suse.com/support/security/rating/","text":"moderate"},"category":"csaf_vex","csaf_version":"2.0","distribution":{"text":"Copyright 2024 SUSE LLC. All rights reserved.","tlp":{"label":"WHITE","url":"https://www.first.org/tlp/"}},"lang":"en","notes":[{"category":"summary","text":"SUSE CVE-2021-21274","title":"Title"},{"category":"description","text":"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 1.25.0, 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. Issue is resolved in version 1.25.0. As a workaround the `federation_domain_whitelist` setting can be used to restrict the homeservers communicated with over federation.","title":"Description of the CVE"},{"category":"legal_disclaimer","text":"CSAF 2.0 data is provided by SUSE under the Creative Commons License 4.0 with Attribution (CC-BY-4.0).","title":"Terms of use"}],"publisher":{"category":"vendor","contact_details":"https://www.suse.com/support/security/contact/","name":"SUSE Product Security Team","namespace":"https://www.suse.com/"},"references":[{"category":"external","summary":"CVE-2021-21274","url":"https://www.suse.com/security/cve/CVE-2021-21274"},{"category":"external","summary":"SUSE Security Ratings","url":"https://www.suse.com/support/security/rating/"},{"category":"external","summary":"SUSE Bug 1182895 for CVE-2021-21274","url":"https://bugzilla.suse.com/1182895"}],"title":"SUSE CVE CVE-2021-21274","tracking":{"current_release_date":"2025-02-17T05:47:11Z","generator":{"date":"2023-02-15T03:46:25Z","engine":{"name":"cve-database.git:bin/generate-csaf-vex.pl","version":"1"}},"id":"CVE-2021-21274","initial_release_date":"2023-02-15T03:46:25Z","revision_history":[{"date":"2023-02-15T03:46:25Z","number":"2","summary":"Current version"},{"date":"2025-01-01T04:46:32Z","number":"3","summary":"Current version"},{"date":"2025-02-15T05:21:00Z","number":"4","summary":"Current version"},{"date":"2025-02-17T05:47:11Z","number":"5","summary":"Current version"}],"status":"interim","version":"5"}}}