{"id":"CVE-2021-21799","aliases":["EUVD-2021-8971","GHSA-4jqw-vm5q-2f6h"],"status":"published","title":"Cross-site scripting vulnerabilities exist in the telnet_form.php script functionality of...","description":"Cross-site scripting vulnerabilities exist in the telnet_form.php script functionality of Advantech R-SeeNet v 2.4.12 (20.10.2020). If a user visits a specially crafted URL, it can lead to arbitrary JavaScript code execution in the context of the targeted user’s browser. An attacker can provide a crafted URL to trigger this vulnerability.","severity":{"version":"3.0","score":9.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.12293,"percentile":0.96217,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2021-07-16T10:33:51Z","modified":"2026-06-17T03:36:08Z","exploits":[{"source":"nuclei","id":"CVE-2021-21799","title":"Advantech R-SeeNet 2.4.12 - Cross-Site Scripting","type":"detection template","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-21799.yaml"}],"products":[{"vendor":"advantech","product":"r-seenet"}],"references":[{"url":"https://talosintelligence.com/vulnerability_reports/TALOS-2021-1270","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21799"},{"url":"https://github.com/advisories/GHSA-4jqw-vm5q-2f6h"}],"sources":{"cve":[{"id":"CVE-2021-21799","description":"Cross-site scripting vulnerabilities exist in the telnet_form.php script functionality of Advantech R-SeeNet v 2.4.12 (20.10.2020). If a user visits a specially crafted URL, it can lead to arbitrary JavaScript code execution in the context of the targeted user’s browser. An attacker can provide a crafted URL to trigger this vulnerability.","status":"published","published":"2021-07-16T10:33:51Z","modified":"2024-08-03T18:23:29.559Z","cvss":[{"version":"3.0","score":9.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:33:00.137099Z"}],"euvd":[{"id":"EUVD-2021-8971","description":"Cross-site scripting vulnerabilities exist in the telnet_form.php script functionality of Advantech R-SeeNet v 2.4.12 (20.10.2020). If a user visits a specially crafted URL, it can lead to arbitrary JavaScript code execution in the context of the targeted user’s browser. An attacker can provide a crafted URL to trigger this vulnerability.","status":"published","published":"2021-07-16T10:33:51Z","modified":"2024-08-03T18:23:29Z","cvss":[{"version":"3.0","score":9.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-03T03:25:05.131984Z"}],"ghsa":[{"id":"GHSA-4jqw-vm5q-2f6h","title":"Cross-site scripting vulnerabilities exist in the telnet_form.php script functionality of...","description":"Cross-site scripting vulnerabilities exist in the telnet_form.php script functionality of Advantech R-SeeNet v 2.4.12 (20.10.2020). If a user visits a specially crafted URL, it can lead to arbitrary JavaScript code execution in the context of the targeted user’s browser. An attacker can provide a crafted URL to trigger this vulnerability.","status":"published","published":"2022-05-24T22:28:12Z","modified":"2023-01-30T05:05:27Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:47:16.830144Z"}],"nvd":[{"id":"CVE-2021-21799","description":"Cross-site scripting vulnerabilities exist in the telnet_form.php script functionality of Advantech R-SeeNet v 2.4.12 (20.10.2020). If a user visits a specially crafted URL, it can lead to arbitrary JavaScript code execution in the context of the targeted user’s browser. An attacker can provide a crafted URL to trigger this vulnerability.","status":"published","published":"2021-07-16T11:15:09.613Z","modified":"2026-06-17T03:36:08.393Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"},{"version":"3.0","score":9.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical","assessor":"secondary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:06:55.747384Z"}]}}