Memory leak in H.323 Gatekeeper Service in Microsoft Internet Security and Acceleration (ISA) Server 2000 allows remote attackers to cause a denial of service (resource exhaustion) via a large amount of malformed H.323 data.
Conclusion & alert: CVE-2001-0546 is rated Moderate Risk (56.1/100): CVSS Medium severity, with high exploitation likelihood (EPSS 19.07%, 95th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +2.93% over the last day, indicating growing attacker interest. 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 | 2025-03-30 | 16.14% | 19.07% | +2.93% |
| 2 | 2025-03-29 | 19.07% | 16.14% | -2.93% |
| 3 | 2025-03-19 | — | 19.07% | — |
Full EPSS history (8 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 | isa_server | 2000 | cpe:2.3:a:microsoft:isa_server:2000:*:*:*:*:*:*:* |