#VU109215 Cross-site scripting in MDaemon - CVE-2025-3929

Vulnerability identifier: #VU109215

Vulnerability risk: High

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Amber]

CVE-ID: CVE-2025-3929

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
MDaemon
Server applications / Mail servers

Vendor: Alt-N

Description

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data when handling IMG tag inside email messages. A remote attacker can trick the victim into opening a specially crafted email message and execute arbitrary JavaScript code in user's browser in context of vulnerable website.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

MDaemon: 20.0.0, 20.0.1, 20.0.2, 20.0.3, 20.0.4, 20.0.5, 20.0.6, 20.0.7, 20.0.8, 20.0.9, 21.0.0, 21.0.1, 21.0.2, 21.0.3, 21.0.4, 21.0.5, 21.0.6, 21.0.7, 21.0.8, 21.5.0, 21.5.1, 21.5.2, 21.5.3, 21.5.4, 21.5.5, 21.5.6, 22.0.0, 22.0.1, 22.0.2, 22.0.3, 22.0.4, 22.0.5, 22.0.6, 22.0.7, 23.0.0, 23.0.1, 23.0.2, 23.0.3, 23.0.4, 23.5.0, 23.5.1, 23.5.2, 23.5.3, 23.5.4, 23.5.5, 24.0.0, 24.0.1, 24.0.2, 24.0.3, 24.0.4, 24.5.0, 24.5.1, 24.5.2, 24.5.3, 25.0.0, 25.0.1

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External links
https://mdaemon.com/pages/downloads-critical-updates
https://files.mdaemon.com/mdaemon/release/RelNotes_en.html

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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.