#VU102787 Use-after-free in Windows and Windows Server - CVE-2025-21298

Vulnerability identifier: #VU102787

Vulnerability risk: High

CVSSv4.0: 7.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: CVE-2025-21298

CWE-ID: CWE-416

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
Windows
Operating systems & Components / Operating system
Windows Server
Operating systems & Components / Operating system

Vendor: Microsoft

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in Windows OLE when handling RTF ibjects. A remote attacker can trick a victim to open a specially crafted email and execute arbitrary code on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Windows: before 10 21H2, 10 22H2, 10 1507, 10 1607, 10 1809, 11 22H2, 11 23H2, 11 24H2, 10 21H2, 10 21H2, 10 21H2, 10 21H2, 10 21H2, 10 21H2, 10 21H2, 10 21H2

Windows Server: before 2008 R2, 2008, 2012 R2, 2012, 2016, 2022 23H2, 2022, 2025, 2008 R2, 2008 R2, 2008 R2, 2008 R2, 2008 R2

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External links
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21298
https://www.zerodayinitiative.com/advisories/ZDI-25-028/

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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. However, proof of concept for this vulnerability is available.