{"id":"CVE-2023-32683","summary":"URL deny list bypass via oEmbed and image URLs when generating previews in Synapse","details":"Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. A discovered oEmbed or image URL can bypass the `url_preview_url_blacklist` setting potentially allowing server side request forgery or bypassing network policies. Impact is limited to IP addresses allowed by the `url_preview_ip_range_blacklist` setting (by default this only allows public IPs) and by the limited information returned to the client: 1. For discovered oEmbed URLs, any non-JSON response or a JSON response which includes non-oEmbed information is discarded. 2. For discovered image URLs, any non-image response is discarded. Systems which have URL preview disabled (via the `url_preview_enabled` setting) or have not configured a `url_preview_url_blacklist` are not affected. This issue has been addressed in version 1.85.0. Users are advised to upgrade. User unable to upgrade may also disable URL previews.","aliases":["GHSA-98px-6486-j7qc","PYSEC-2023-85"],"modified":"2026-04-10T04:58:05.628343Z","published":"2023-06-06T18:24:30.457Z","related":["openSUSE-SU-2024:13039-1"],"database_specific":{"cwe_ids":["CWE-863"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/32xxx/CVE-2023-32683.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/X6DH5A5YEB5LRIPP32OUW25FCGZFCZU2/"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/32xxx/CVE-2023-32683.json"},{"type":"ADVISORY","url":"https://github.com/matrix-org/synapse/security/advisories/GHSA-98px-6486-j7qc"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-32683"},{"type":"FIX","url":"https://github.com/matrix-org/synapse/pull/15601"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/matrix-org/synapse","events":[{"introduced":"0"},{"fixed":"ec71214243eac58a4a6d272c15441a6405f6ae9c"}]}],"versions":["hhs-1","hhs-2","hhs-3","hhs-5","hhs-6","hhs-7","hhs-8","v0.10.0","v0.10.0-r1","v0.10.0-r2","v0.11.0","v0.11.0-r1","v0.11.0-r2","v0.11.1","v0.12.0","v0.13.1","v0.13.2","v0.13.3","v0.14.0","v0.16.0","v0.16.1","v0.16.1-r1","v0.17.0","v0.17.1","v0.17.2","v0.17.3","v0.18.0","v0.18.1","v0.18.2","v0.18.3","v0.18.4","v0.18.5","v0.2.0","v0.2.1","v0.2.1a","v0.2.2","v0.23.0-rc1","v0.23.0-rc2","v0.25.0-rc1","v0.28.0-rc1","v0.3.0","v0.3.3","v0.3.4","v0.32.0","v0.32.0rc1","v0.32.2","v0.4.1","v0.4.2","v0.5.0","v0.5.1","v0.5.2","v0.5.3","v0.5.3a","v0.5.3b","v0.5.3c","v0.5.4","v0.5.4a","v0.6.0","v0.6.0a","v0.6.0b","v0.6.1","v0.6.1a","v0.6.1b","v0.6.1c","v0.6.1d","v0.6.1e","v0.6.1f","v0.7.0","v0.7.0a","v0.7.0b","v0.7.0c","v0.7.0d","v0.7.0e","v0.7.0f","v0.7.1","v0.7.1-r1","v0.7.1-r2","v0.7.1-r3","v0.7.1-r4","v0.8.0","v0.8.1","v0.8.1-r1","v0.8.1-r2","v0.8.1-r3","v0.8.1-r4","v0.9.0","v0.9.0-r1","v0.9.0-r2","v0.9.0-r3","v0.9.0-r4","v0.9.0-r5","v0.9.1","v0.9.2","v0.9.2-r1","v0.9.2-r2","v0.9.3","v0.99.1rc1","v0.99.2rc1","v0.99.4rc1","v0.99.5.1.dev0","v1.1.0rc1","v1.1.0rc2","v1.10.0rc1","v1.11.0rc1","v1.12.0rc1","v1.14.0rc1","v1.15.0rc1","v1.16.0rc1","v1.17.0rc1","v1.18.0rc1","v1.23.0rc1","v1.24.0rc1","v1.27.0rc1","v1.29.0rc1","v1.3.0rc1","v1.30.0rc1","v1.31.0rc1","v1.32.0rc1","v1.34.0rc1","v1.35.0rc1","v1.36.0rc1","v1.4.0rc1","v1.40.0rc1","v1.49.0rc1","v1.5.0rc1","v1.52.0rc1","v1.6.0rc1","v1.62.0rc1","v1.63.0rc1","v1.75.0rc1","v1.76.0rc1","v1.78.0rc1","v1.79.0rc1","v1.8.0rc1","v1.81.0rc1","v1.84.0rc1","v1.85.0rc1","v1.85.0rc2","v1.9.0.dev1","v1.9.0.dev2","v1.9.0rc1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-32683.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N"}]}