Heap-based buffer overflow in the Siemens WinCC Runtime Advanced Loader, as used in SIMATIC WinCC flexible Runtime and SIMATIC WinCC (TIA Portal) Runtime Advanced, allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via a crafted packet to TCP port 2308.
Conclusion & alert: CVE-2011-3321 is rated High Risk (66.3/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 2.70%). Mandatory action: High exploitation likelihood—assess exposure and prioritize 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 | 2025-10-20 | 3.50% | 2.70% | -0.79% |
| 2 | 2025-08-06 | 4.11% | 3.50% | -0.61% |
| 3 | 2025-05-16 | — | 4.11% | — |
Full EPSS history (14 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.3 | 2.0 | HIGH |
|
8.6 | 10.0 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| siemens | simatic_wincc_flexible_runtime | — | cpe:2.3:a:siemens:simatic_wincc_flexible_runtime:*:*:*:*:*:*:*:* |
| siemens | simatic_wincc_runtime | — | cpe:2.3:a:siemens:simatic_wincc_runtime:-:*:*:*:advanced:*:*:* |