{"cve":"CVE-2023-51447","nvd":{"published":"2024-02-20T18:15:50.547","modified":"2026-06-17T06:40:58.690","status":"Analyzed","description":"Decidim is a participatory democracy framework. Starting in version 0.27.0 and prior to versions 0.27.5 and 0.28.0, the dynamic file upload feature is subject to potential cross-site scripting attacks in case the attacker manages to modify the file names of the records being uploaded to the server. This appears in sections where the user controls the file upload dialogs themselves and has the technical knowledge to change the file names through the dynamic upload endpoint. Therefore I believe it would require the attacker to control the whole session of the particular user but in any case, this needs to be fixed. Successful exploit of this vulnerability would require the user to have successfully uploaded a file blob to the server with a malicious file name and then have the possibility to direct the other user to the edit page of the record where the attachment is attached. The users are able to craft the direct upload requests themselves controlling the file name that gets stored to the database. The attacker is able to change the filename e.g. to `<svg onload=alert('XSS')>` if they know how to craft these requests themselves. And then enter the returned blob ID to the form inputs manually by modifying the edit page source. Versions 0.27.5 and 0.28.0 contain a patch for this issue. As a workaround, disable dynamic uploads for the instance, e.g. from proposals.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","score":5.4},"cwes":["CWE-79"],"references":["https://github.com/decidim/decidim/commit/aaf72787cf18beeeb6a771c1f7cbb7654b073423","https://github.com/decidim/decidim/pull/11612","https://github.com/decidim/decidim/releases/tag/v0.27.5","https://github.com/decidim/decidim/releases/tag/v0.28.0","https://github.com/decidim/decidim/security/advisories/GHSA-9w99-78rj-hmxq"],"products":["decidim:decidim"],"source":"nvd","synced_at":"2026-10-19T21:45:59.823092188+00:00"},"epss":{"cve":"CVE-2023-51447","score":0.00493,"percentile":0.42357,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-9w99-78rj-hmxq","url":"https://osv.dev/vulnerability/GHSA-9w99-78rj-hmxq","summary":"Cross-site scripting (XSS) in the dynamic file uploads","modified":"2024-02-20T23:56:34.783273Z","packages":[{"ecosystem":"RubyGems","name":"decidim","purl":"pkg:gem/decidim","ranges":[">=0.27.0 <0.27.5"],"fixed":["0.27.5"]},{"ecosystem":"RubyGems","name":"decidim-core","purl":"pkg:gem/decidim-core","ranges":[">=0.27.0 <0.27.5"],"fixed":["0.27.5"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}