The Microsoft Security Response Center issued a security warning yesterday about a denial of service (DOS) issue affecting Internet Information Services (IIS) Services), the technology used by Microsoft's web servers.
According to microphonesοft, οι διακομιστές IIS που λειτουργούν με windows 10 and Windows Server & Hosting 2016 are affected by the vulnerability when processing HTTP / 2 requests.
HTTP/2 is the latest version of the HTTP protocol that supports the World Wide Web (www), the part of the internet that normal users can access through browsers.
Microsoft reports that IIS servers that process HTTP / 2 requests can cause CPU usage to 100%, slowing down the entire system.
Gal Goldshtein, software engineer at F5 Networks, was the one who discovered the problem. It is worth mentioning that in addition to the security warning ADV190005 released by Microsoft, to date no other information is available on this vulnerability.
Cumulative updates KB4487006, KB4487011, KB4487021 and KB4487029 released two days ago are supposed to fix the bug of services IIS we mentioned above.
According to the company, after the updates are implemented, IIS administrators will be able to adjust the HTTP / 2 request threshold and prevent the error caused by IIS freezing and a vertical increase in system CPU resources.
"Limits must be set by the IIS administrator," the company said, "not set by Microsoft."
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