SB2021060814 - Multiple vulnerabilities in Microsoft Office Graphics

Description

This security bulletin contains information about 2 vulnerabilities.

1) Code Injection (CVE-ID: CVE-2021-31940)

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in Microsoft Office Graphics. A remote attacker can trick a victim to open a specially crafted file or visit a malicious website and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

2) Use-after-free (CVE-ID: CVE-2021-31941)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error when processing Excel files in Microsoft Office Graphics. A remote attacker can create a specially crafted Excel file, trick the victim into opening it, trigger a use-after-free error and execute arbitrary code on the system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31940
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31941
• https://www.zerodayinitiative.com/advisories/ZDI-21-669/