The Windows NT Client Server Runtime Subsystem (CSRSS) can be subjected to a denial of service when all worker threads are waiting for user input.
https://docs.microsoft.com/en-us/security-updates/securitybulletins/1999/ms99-021
http://support.microsoft.com/default.aspx?scid=kb%3B%5BLN%5D%3BQ233323
http://www.securityfocus.com/bid/478
http://www.ciac.org/ciac/bulletins/j-049.shtml
Source: Mitre, NVD
Published: 1999-06-23
Updated: 2026-06-16
Base Score: 7.1
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:C
Severity: High
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.07357