Threat Signal Report

Proof-of-Concept Code Now Available for an Exploited Windows Local Privilege Escalation Vulnerability

description-logo Description

FortiGuard Labs is aware that a Proof-of-Concept (POC) code for a newly patched Windows vulnerability (CVE-2022-21882) that is reported to have been exploited in the wild was released to a publicly available online repository. CVE-2022-21882 is a local privilege (LPE) escalation vulnerability which allows a local, authenticated attacker to gain elevated local system or administrator privileges through a vulnerability in the Win32k.sys driver. The vulnerability is rated as Important by Microsoft and has CVSS score of 7.0.


Why is this Significant?

This is significant because now that the POC for CVE-2022-21882 has become available to the public attacks leveraging the vulnerability will likely increase. Because CVE-2022-21882 is a local privilege escalation the vulnerability will be used by an attacker that already has access to the network or will be chained with other vulnerabilities.


What is CVE-2022-21882?

CVE-2022-21882 is a local privilege (LPE) escalation vulnerability which allows a local, authenticated attacker to gain elevated local system or administrator privileges through a vulnerability in the Win32k.sys driver.


Is the Vulnerability Exploited in the Wild?

According to the Microsoft advisory, the vulnerability is being exploited in the wild.


Has Microsoft Released an Advisory for CVE-2022-21882?

Yes. See the Appendix for a link to the advisory.


Has Microsoft Released a fix for CVE-2022-21882?

Yes. Microsoft has released a patch as part of regular MS Tuesday on January 11th, 2022.


What is the Status of Coverage?

FortiGuard Labs provide the following IPS coverage for CVE-2022-21882:


MS.Windows.Win32k.CVE-2022-21882.Privilege.Elevation


FortiGuard Labs has released the following AV coverage based on the available POC:


W64/Agent.A93E!exploit.CVE202221882


Definitions

Traffic Light Protocol

Color When Should it Be used? How may it be shared?

TLP: RED

Not for disclosure, restricted to participants only.
Sources may use TLP:RED when information cannot be effectively acted upon by additional parties, and could lead to impacts on a party's privacy, reputation, or operations if misused. Recipients may not share TLP:RED information with any parties outside of the specific exchange, meeting, or conversation in which it was originally disclosed. In the context of a meeting, for example, TLP:RED information is limited to those present at the meeting. In most circumstances, TLP:RED should be exchanged verbally or in person.

TLP: AMBER

Limited disclosure, restricted to participants’ organizations.
Sources may use TLP:AMBER when information requires support to be effectively acted upon, yet carries risks to privacy, reputation, or operations if shared outside of the organizations involved. Recipients may only share TLP:AMBER information with members of their own organization, and with clients or customers who need to know the information to protect themselves or prevent further harm. Sources are at liberty to specify additional intended limits of the sharing: these must be adhered to.

TLP: GREEN

Limited disclosure, restricted to the community.
Sources may use TLP:GREEN when information is useful for the awareness of all participating organizations as well as with peers within the broader community or sector. Recipients may share TLP:GREEN information with peers and partner organizations within their sector or community, but not via publicly accessible channels. Information in this category can be circulated widely within a particular community. TLP:GREEN information may not be released outside of the community.

TLP: WHITE

Disclosure is not limited.
Sources may use TLP:WHITE when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:WHITE information may be distributed without restriction.