Buffer overflow in Microsoft command processor (CMD.EXE) for Windows NT and Windows 2000 allows a local user to cause a denial of service via a long environment variable, aka the "Malformed Environment Variable" vulnerability.
Conclusion & alert: CVE-2000-0331 is rated Moderate Risk (53.7/100): CVSS Medium severity, with high exploitation likelihood (EPSS 8.19%, 94th 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 | 2026-06-20 | 7.45% | 8.19% | +0.74% |
| 2 | 2026-06-15 | 17.18% | 7.45% | -9.73% |
| 3 | 2025-12-28 | — | 17.18% | — |
Full EPSS history (16 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | terminal_server | — | cpe:2.3:a:microsoft:terminal_server:*:*:*:*:*:*:*:* |
| microsoft | windows_2000 | — | cpe:2.3:o:microsoft:windows_2000:*:*:*:*:*:*:*:* |
| microsoft | windows_nt | 4.0 | cpe:2.3:o:microsoft:windows_nt:4.0:*:*:*:*:*:*:* |