#VU102798 Untrusted Pointer Dereference in Microsoft products - CVE-2025-21354

Vulnerability identifier: #VU102798

Vulnerability 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-2025-21354

CWE-ID: CWE-822

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Office Online Server
Server applications / Other server solutions
Microsoft Office
Client/Desktop applications / Office applications
Microsoft 365 Apps for Enterprise
Client/Desktop applications / Office applications
Microsoft Office LTSC
Client/Desktop applications / Other client software

Vendor: Microsoft

Description

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

The vulnerability exists due to untrusted pointer dereference in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted file and execute arbitrary code on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Office Online Server : All versions

Microsoft Office: 2019

Microsoft Office LTSC: 2021 - 2024

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

---

External links
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21354

---

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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