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Vulnerability record · CVE-2021-21800 · published 16 July 2021

CVE-2021-21800: Advantech r-seenet cross-site scripting vulnerability

Advantech · R Seenet

Cross-site scripting vulnerabilities exist in the ssh_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.

6.1 CVSS 3.1 Medium EPSS 14% · top 3.6% CWE-79 · Cross-site scripting
6.1CVSS 3.1 base score, v2 4.3
14%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

Cross-site scripting vulnerabilities exist in the ssh_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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1271 ExploitThird Party Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1271 ExploitThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2023-5642Advantech r-seenet information exposure vulnerabilityAdvantech R-SeeNet v2.4.23 allows an unauthenticated remote attacker to read from and write to the snmpmon.ini file, which contains sensitive informa…EPSS 17%9.8CVE-2023-2611Advantech r-seenet hard-coded credentials vulnerabilityAdvantech R-SeeNet versions 2.4.22 is installed with a hidden root-level user that is not available in the users list. This hidden user has a passwor…EPSS 0.67%9.8CVE-2022-3385Advantech r-seenet stack-based buffer overflow vulnerabilityAdvantech R-SeeNet Versions 2.4.17 and prior are vulnerable to a stack-based buffer overflow. An unauthorized attacker can remotely overflow the stac…EPSS 1.3%9.8CVE-2022-3386Advantech r-seenet stack-based buffer overflow vulnerabilityAdvantech R-SeeNet Versions 2.4.17 and prior are vulnerable to a stack-based buffer overflow. An unauthorized attacker can use an outsized filename t…EPSS 1.3%9.8CVE-2021-21805Advantech R-SeeNet ping.php OS command injectionAdvantech R-SeeNet v2.4.12 (20.10.2020) contains an OS command injection flaw in the ping.php script. A crafted HTTP request can cause arbitrary OS c…EPSS 70%analysed9.8CVE-2021-21804Advantech r-seenet php remote file inclusion vulnerabilityA local file inclusion (LFI) vulnerability exists in the options.php script functionality of Advantech R-SeeNet v 2.4.12 (20.10.2020). A specially cr…EPSS 3.7%8.8CVE-2021-21915Advantech r-seenet sql injection vulnerabilityAn exploitable SQL injection vulnerability exist in the ‘group_list’ page of the Advantech R-SeeNet 2.4.15 (30.07.2021). A specially-crafted HTTP req…EPSS 1.4%8.8CVE-2021-21916Advantech r-seenet sql injection vulnerabilityAn exploitable SQL injection vulnerability exist in the ‘group_list’ page of the Advantech R-SeeNet 2.4.15 (30.07.2021). A specially-crafted HTTP req…EPSS 1.4%

Source: NIST National Vulnerability Database (record CVE-2021-21800), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.