A denial of service vulnerability exists in the HTTP/2 protocol stack (HTTP.sys) when HTTP.sys improperly parses specially crafted HTTP/2 requests. An attacker who successfully exploited the vulnerability could create a denial of service condition, causing the target system to become unresponsive.
To exploit this vulnerability, an unauthenticated attacker could send a specially crafted HTTP packet to a target system, causing the affected system to become nonresponsive.
The update addresses the vulnerability by modifying how the Windows HTTP protocol stack handles HTTP/2 requests. Note that the denial of service vulnerability would not allow an attacker to execute code or to elevate user rights.