CVE-2020-11711

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.

Published: 2023-08-25 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-11711 is rated Low Risk (30.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.40%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-11711

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.49% 0.40% -0.09%
2 2026-05-20 0.36% 0.49% +0.13%
3 2025-11-21 0.36%

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-11711

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
1.7 2.7 [email protected]

Weakness enumeration for CVE-2020-11711

Affected software / configurations for CVE-2020-11711

Vendor Product Version Raw CPE
stormshield stormshield_network_security >= 3.6.0, < 3.7.13 cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:*
stormshield stormshield_network_security >= 3.8.0, < 3.11.0 cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:*
stormshield stormshield_network_security >= 4.0.0, < 4.1.1 cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:*

References for CVE-2020-11711

cvelogic Threat Intelligence