SB2021121473 - Multiple vulnerabilities in Microsoft Windows Encrypting File System (EFS)

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2021-43893)

The vulnerability allows a remote authenticated attacker to escalate privileges on the system.

The vulnerability exists due to application does not properly impose security restrictions in Windows Encrypting File System (EFS), which leads to security restrictions bypass and privilege escalation.

2) Out-of-bounds write (CVE-ID: CVE-2021-43217)

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing untrusted input in Windows Encrypting File System (EFS). A remote attacker can trigger out-of-bounds write and execute arbitrary code on the target system.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43893
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43217