Microsoft Windows 8/8.1/10/11 Unicode Zalgo resource consumption ⚔ [Disputed]

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Microsoft Windows 8/8.1/10/11. This impacts an unknown function of the component Unicode Handler. This manipulation causes resource consumption. This vulnerability is handled as CVE-2017-20190. The attack can be initiated remotely. Additionally, an exploit exists. The actual existence of this vulnerability is currently in question.

Detailsinfo

A vulnerability was found in Microsoft Windows 8/8.1/10/11. It has been declared as problematic. Affected by this vulnerability is an unknown functionality of the component Unicode Handler. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. The summary by CVE is:

Some Microsoft technologies as used in Windows 8 through 11 allow a temporary client-side performance degradation during processing of multiple Unicode combining characters, aka a "Zalgo text" attack. NOTE: third parties dispute whether the computational cost of interpreting Unicode data should be considered a vulnerability.

It is possible to read the advisory at talk.dynalist.io. This vulnerability is known as CVE-2017-20190 since 03/26/2024. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are unknown but a public exploit is available. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

It is possible to download the exploit at talk.dynalist.io. It is declared as proof-of-concept. The real existence of this vulnerability is still doubted at the moment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Operating System

Vendor

• Microsoft

Name

• Windows

Version

• 8
• 8.1
• 10
• 11

License

• commercial

Website

• Vendor: https://www.microsoft.com/
• Product: https://www.microsoft.com/en-us/windows

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