Tcpip.sys in the TCP/IP stack in Microsoft Windows Vista SP2, Windows Server 2008 SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 allows remote attackers to cause a denial of service (reboot) via a series of crafted ICMP messages, aka "ICMP Denial of Service Vulnerability."
Conclusion & alert: CVE-2011-1871 is rated Moderate Risk (60.7/100): CVSS High severity, with high exploitation likelihood (EPSS 68.31%, 99th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. 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 | 2025-10-18 | 74.92% | 68.31% | -6.62% |
| 2 | 2025-03-30 | 79.75% | 74.92% | -4.82% |
| 3 | 2025-03-29 | — | 79.75% | — |
Full EPSS history (22 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.8 | 2.0 | HIGH |
|
10.0 | 6.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | windows_7 | — | cpe:2.3:o:microsoft:windows_7:-:*:*:*:*:*:*:* |
| microsoft | windows_7 | — | cpe:2.3:o:microsoft:windows_7:-:sp1:x64:*:*:*:*:* |
| microsoft | windows_7 | — | cpe:2.3:o:microsoft:windows_7:-:sp1:x86:*:*:*:*:* |
| microsoft | windows_server_2008 | — | cpe:2.3:o:microsoft:windows_server_2008:*:sp2:x32:*:*:*:*:* |
| microsoft | windows_server_2008 | — | cpe:2.3:o:microsoft:windows_server_2008:*:sp2:x64:*:*:*:*:* |
| microsoft | windows_server_2008 | — | cpe:2.3:o:microsoft:windows_server_2008:-:sp2:itanium:*:*:*:*:* |
| microsoft | windows_server_2008 | r2 | cpe:2.3:o:microsoft:windows_server_2008:r2:*:itanium:*:*:*:*:* |
| microsoft | windows_server_2008 | r2 | cpe:2.3:o:microsoft:windows_server_2008:r2:*:x64:*:*:*:*:* |
| microsoft | windows_vista | — | cpe:2.3:o:microsoft:windows_vista:*:sp2:*:*:*:*:*:* |