Stormshield Network Security (SNS) 3.x has an Integer Overflow in the high-availability component.
Conclusion & alert: CVE-2021-3398 is rated Moderate Risk (43.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.91%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
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 | 0.33% | 0.91% | +0.58% |
| 2 | 2025-03-30 | 0.53% | 0.33% | -0.20% |
| 3 | 2025-03-29 | — | 0.53% | — |
Full EPSS history (6 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.8 | 3.1 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| stormshield | stormshield_network_security | >= 3.0.0, <= 3.7.24 | cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:* |
| stormshield | stormshield_network_security | >= 3.8.0, <= 3.11.12 | cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://advisories.stormshield.eu/2021-001/ | Vendor Advisory |
| https://www.stormshield.com/category/alert/ | Vendor Advisory |