CVE-2020-11711
CWE-79Published: August 25, 2023· Updated: Jun 17, 2026
Official Description
An issue was discovered in Stormshield SNS 3.8.0. Authenticated Stored XSS in the admin login panel leads to SSL VPN credential theft. A malicious disclaimer file can be uploaded from the admin panel. The resulting file is rendered on the authentication interface of the admin panel. It is possible to inject malicious HTML content in order to execute JavaScript inside a victim's browser. This results in a stored XSS on the authentication interface of the admin panel. Moreover, an unsecured authentication form is present on the authentication interface of the SSL VPN captive portal. Users are allowed to save their credentials inside the browser. If an administrator saves his credentials through this unsecured form, these credentials could be stolen via the stored XSS on the admin panel without user interaction. Another possible exploitation would be modification of the authentication form of the admin panel into a malicious form.
Technical Analysis
CVE-2020-11711 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (6)
Quick Facts
Related CVEs (CWE-79)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-11711 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts