Spoofing attack in Microsoft Outlook

1) Spoofing attack

EUVDB-ID: #VU103829

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-21259

CWE-ID: CWE-451 - User Interface (UI) Misrepresentation of Critical Information (Clickjacking, spoofing)

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to incorrect processing of user-supplied data in Microsoft Outlook. A remote attacker's message can inherit the sender's email address from another message in the UI.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Outlook for Android: All versions

CPE2.3

• cpe:2.3:a:microsoft:com.microsoft.office.outlook:*:*:*:*:*:android:*:*

External links

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21259

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 perform certain actions on the device.

Is there known malware, which exploits this vulnerability?

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