Cross-Site Scripting (XSS) in Sagemcom F@ST3686 (CVE-2020-21733)
Summary
Cross-site scripting in Sagemcom F@ST3686 (CVE-2020-21733). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
Sagemcom F@ST3686 v1.0 HUN 3.97.0 has XSS via RgDiagnostics.asp, RgDdns.asp, RgFirewallEL.asp, RgVpnL2tpPptp.asp.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2020-21733 has been found in Sagemcom F@ST3686.
Risk of unauthorized operations or information disclosure. CVSS score: 6.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Sagemcom F@ST3686 CVE-2020-21733" on the vendor's site.
CVE-2020-21733 (Sagemcom F@ST3686) — CWE-79 / CVSS v3 6.1
Attack vector: remote (network-reachable) / unauthenticated
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in Sagemcom F@ST3686.
Check the vendor advisory for the affected versions of Sagemcom F@ST3686.
Severity: Medium (CVSS 6.1/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Sagemcom F@ST3686 を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- exploit github.com
- exploit github.com
- patch sagemcom.com
- web nvd.nist.gov
- web sagemcomfst3686v10hun3970.com
- web github.com