Remote code execution in Microsoft Word

1) Out-of-bounds write

EUVDB-ID: #VU86482

Risk: High

CVSSv4.0: 5.7 [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]

CVE-ID: CVE-2024-21379

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing PDF files with Microsoft Word. A remote attacker can create a specially crafted PDF file, trick the victim into opening it using the affected software, trigger an out-of-bounds write and execute arbitrary code on the target system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Office: 2019

Microsoft Word: 2016

Microsoft Office LTSC: 32 bit editions - 64 bit editions

Microsoft 365 Apps for Enterprise: 32-bit Systems - 64-bit Systems

CPE2.3

• cpe:2.3:a:microsoft:microsoft_office:*:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_word:*:*:*:*:*:microsoft_office:*:*
• cpe:2.3:a:microsoft:microsoft_office_ltsc:32:bit editions:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_office_ltsc:64:bit editions:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:32-bit_Systems:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise:64-bit_Systems:*:*:*:*:*:*:*

External links

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21379
https://www.zerodayinitiative.com/advisories/ZDI-24-164/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to visit a specially crafted website or open a file.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.