Microsoft Security Response Center

**What type of information could be disclosed by this vulnerability?** The type of information that could be disclosed if an attacker successfully exploited this vulnerability is uninitialized memory.

**Why is this a MITRE Corporation CVE?** CVE-2021-36976 is regarding a vulnerability in the libarchive open source library which is used by Windows. The January 2022 Windows Security Updates include the most recent version of this library which addresses the vulnerability and others. Please see libarchive CVEs for more information regarding all of the vulnerabilities that have been addressed.

**Why is this a Hacker One CVE?** This CVE is regarding a vulnerability in the curl open source library which is used by Windows. The January 2022 Windows Security Updates includes the most recent version of this library which addresses the vulnerability and others. Please see curl security problems for information on all of the vulnerabilities that have been addressed.

**What privileges does the attacker gain?** An attacker would only be able to delete targeted files on a system. They would not gain privileges to view or modify file contents.

**What security feature is bypassed with this vulnerability?** A successful attacker could bypass the WPBT binary verification by using a small number of compromised certificates. Microsoft has added those certificates to the Windows kernel driver block list, driver.stl. Certificates on the driver.stl will be blocked even if present in the Windows Platform Binary Table (WPBT). In addition, Microsoft recommends customers use Windows Defender Application Control (WDAC) to limit what is allowed to run on their devices. WDAC policy is also enforced for binaries included in the WPBT and should mitigate this issue. We recommend customers implement a WDAC policy that is as restrictive as practical for their environment. You can find documentation on WDAC on https://docs.microsoft.com.

**Where can I get more information?** Please see 5010265 for more information about how to protect yourself.

**What is the version information for this release?** Microsoft Edge Version Date Released Based on Chromium Version 97.0.1072.55 1/6/2022 97.0.4692.71

**What is the version information for this release?** Microsoft Edge Version Date Released Based on Chromium Version 97.0.1072.55 1/6/2022 97.0.4692.71

**What is the version information for this release?** Microsoft Edge Version Date Released Based on Chromium Version 97.0.1072.55 1/6/2022 97.0.4692.71

**What is the version information for this release?** Microsoft Edge Version Date Released Based on Chromium Version 97.0.1072.55 1/6/2022 97.0.4692.71