CVE-1999-0721

Denial of service in Windows NT Local Security Authority (LSA) through a malformed LSA request.

Published: 1999-07-20 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-1999-0721 is rated High Risk (65.2/100): CVSS High severity, with high exploitation likelihood (EPSS 9.37%, 95th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. 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.

Exploit prediction scoring system (EPSS) score for CVE-1999-0721

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 8.53% 9.37% +0.84%
2 2026-06-15 18.91% 8.53% -10.38%
3 2025-12-28 — 18.91% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-1999-0721

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 2.0 HIGH
AV:N/AC:L/Au:N/C:N/I:N/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 6.9 [email protected]

Weakness enumeration for CVE-1999-0721

Affected software / configurations for CVE-1999-0721

Vendor Product Version Raw CPE
microsoft windows_2000 — cpe:2.3:o:microsoft:windows_2000:*:*:*:*:*:*:*:*
microsoft windows_nt — cpe:2.3:o:microsoft:windows_nt:*:*:*:*:*:*:*:*
microsoft windows_nt 4.0 cpe:2.3:o:microsoft:windows_nt:4.0:sp4:*:*:*:*:*:*
microsoft windows_nt 4.0 cpe:2.3:o:microsoft:windows_nt:4.0:sp5:*:*:*:*:*:*

References for CVE-1999-0721

cvelogic Threat Intelligence