{"id":"CVE-2021-28428","aliases":["EUVD-2021-15107","GHSA-cm95-9q8x-72h6"],"status":"published","title":"File upload vulnerability in HorizontCMS before 1.0.0-beta.3 via uploading a .htaccess and *...","description":"File upload vulnerability in HorizontCMS before 1.0.0-beta.3 via uploading a .htaccess and *.hello files using the Media Files upload functionality. The original file upload vulnerability (CVE-2020-27387) was remediated by restricting the PHP extensions; however, we confirmed that the filter was bypassed via uploading an arbitrary .htaccess and *.hello files in order to execute PHP code to gain RCE.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.01243,"percentile":0.69623,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-434"],"published":"2022-04-05T15:37:31Z","modified":"2026-10-20T10:54:35Z","products":[{"vendor":"horizontcms_project","product":"horizontcms"}],"references":[{"url":"https://github.com/ttimot24/HorizontCMS","tags":["x_refsource_MISC","x_transferred","Product","package"]},{"url":"https://github.com/ttimot24/HorizontCMS/commit/9c4d6827cbe96decec6834d53660e14ab2bf8838","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-28428"},{"url":"https://github.com/advisories/GHSA-cm95-9q8x-72h6"}],"sources":{"cve":[{"id":"CVE-2021-28428","description":"File upload vulnerability in HorizontCMS before 1.0.0-beta.3 via uploading a .htaccess and *.hello files using the Media Files upload functionality. The original file upload vulnerability (CVE-2020-27387) was remediated by restricting the PHP extensions; however, we confirmed that the filter was bypassed via uploading an arbitrary .htaccess and *.hello files in order to execute PHP code to gain RCE.","status":"published","published":"2022-04-05T15:37:31Z","modified":"2024-08-03T21:40:14.223Z","updated_at":"2026-11-02T14:33:09.175141Z"}],"euvd":[{"id":"EUVD-2021-15107","description":"File upload vulnerability in HorizontCMS before 1.0.0-beta.3 via uploading a .htaccess and *.hello files using the Media Files upload functionality. The original file upload vulnerability (CVE-2020-27387) was remediated by restricting the PHP extensions; however, we confirmed that the filter was bypassed via uploading an arbitrary .htaccess and *.hello files in order to execute PHP code to gain RCE.","status":"published","published":"2022-04-05T15:37:31Z","modified":"2024-08-03T21:40:14Z","updated_at":"2026-11-03T03:24:46.751124Z"}],"ghsa":[{"id":"GHSA-cm95-9q8x-72h6","title":"File upload vulnerability in HorizontCMS before 1.0.0-beta.3 via uploading a .htaccess and *...","description":"File upload vulnerability in HorizontCMS before 1.0.0-beta.3 via uploading a .htaccess and *.hello files using the Media Files upload functionality. The original file upload vulnerability (CVE-2020-27387) was remediated by restricting the PHP extensions; however, we confirmed that the filter was bypassed via uploading an arbitrary .htaccess and *.hello files in order to execute PHP code to gain RCE.","status":"published","published":"2022-04-06T00:01:30Z","modified":"2023-01-27T05:01:19Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-434"],"updated_at":"2026-11-02T14:41:52.138061Z"}],"nvd":[{"id":"CVE-2021-28428","description":"File upload vulnerability in HorizontCMS before 1.0.0-beta.3 via uploading a .htaccess and *.hello files using the Media Files upload functionality. The original file upload vulnerability (CVE-2020-27387) was remediated by restricting the PHP extensions; however, we confirmed that the filter was bypassed via uploading an arbitrary .htaccess and *.hello files in order to execute PHP code to gain RCE.","status":"published","published":"2022-04-05T16:15:11.88Z","modified":"2026-06-17T03:46:20.22Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"cwes":["CWE-434"],"updated_at":"2026-11-02T14:07:05.581807Z"}],"osv":[{"id":"CVE-2021-28428","description":"File upload vulnerability in HorizontCMS before 1.0.0-beta.3 via uploading a .htaccess and *.hello files using the Media Files upload functionality. The original file upload vulnerability (CVE-2020-27387) was remediated by restricting the PHP extensions; however, we confirmed that the filter was bypassed via uploading an arbitrary .htaccess and *.hello files in order to execute PHP code to gain RCE.","status":"published","published":"2022-04-05T16:15:11.88Z","modified":"2026-10-20T10:54:35.957783693Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:44:19.129331Z"}]}}