CVE-2021-21799 in the critical feed json
Cross-site scripting vulnerabilities exist in the telnet_form.php script functionality of Advantech R-SeeNet v 2.4.12 (20.10.2020).
published 2021-07-16 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-8971
- cvss
- 9.6
- version 3.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 12.3%
- EPSS 12.3% chance of exploitation in 30 days, percentile 96%
- public exploits
- 0
- none known, plus a Nuclei check
Summary
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.
Exploit prediction
12.29% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- Nuclei template Advantech R-SeeNet 2.4.12 - Cross-Site Scripting nuclei detection template
- talosintelligence.com https://talosintelligence.com/vulnerability_reports/TALOS-2021-1270 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.0 | 9.6 | CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H |
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:N/I:P/A:N |
Affected products
- n/a Advantech
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
talosintelligence.com
/vulnerability_reports/TALOS-2021-1270
exploit, third-party-advisory
Sources
- CVE List CVE-2021-21799
- NVD CVE-2021-21799
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