Cross-site scripting in Sagemcom F@ST 3686

1) Cross-site scripting

EUVDB-ID: #VU46763

Risk: Low

CVSSv3.1: 5.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:U/RC:C]

CVE-ID: CVE-2020-21733

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Exploit availability: No

Description

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data within the "RgDiagnostics.asp", "RgDdns.asp", "RgFirewallEL.asp" and "RgVpnL2tpPptp.asp" fields. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

F@st 3686: 3.97.0

External links

http://sagemcom.com
http://sagemcomfst3686v10hun3970.com
http://github.com/Gr3gPr1est/BugReport/blob/master/CVE-2020-21733
http://github.com/Gr3gPr1est/BugReport/blob/master/SAGEM_F%40ST3686_v1.0_HUN_3.97.0_XSS_Vuln..pdf

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.