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Vulnerability record · CVE-2020-21733 · published 14 September 2020

CVE-2020-21733: Sagemcom f\@st 3686 firmware cross-site scripting vulnerability

Sagemcom · F\@St 3686 Firmware

Sagemcom F@ST3686 v1.0 HUN 3.97.0 has XSS via RgDiagnostics.asp, RgDdns.asp, RgFirewallEL.asp, RgVpnL2tpPptp.asp.

6.1 CVSS 3.1 Medium EPSS 0.73% · top 47.6% CWE-79 · Cross-site scripting
6.1CVSS 3.1 base score, v2 4.3
0.73%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References, 4 tagged exploit
9 Jul 2026Last modified by NVD

Description

Sagemcom F@ST3686 v1.0 HUN 3.97.0 has XSS via RgDiagnostics.asp, RgDdns.asp, RgFirewallEL.asp, RgVpnL2tpPptp.asp.

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://github.com/Gr3gPr1est/BugReport/blob/master/CVE-2020-21733 ExploitThird Party Advisory
https://github.com/Gr3gPr1est/BugReport/blob/master/SAGEM_F%40ST3686_v1.0_HUN_3.97.0_XSS_Vuln..pdf ExploitThird Party Advisory
https://github.com/Gr3gPr1est/BugReport/blob/master/CVE-2020-21733 ExploitThird Party Advisory
https://github.com/Gr3gPr1est/BugReport/blob/master/SAGEM_F%40ST3686_v1.0_HUN_3.97.0_XSS_Vuln..pdf ExploitThird Party Advisory

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Related vulnerabilities

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

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Source: NIST National Vulnerability Database (record CVE-2020-21733), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.