CVE-2025-61084: Input Validation Flaw (CVSS 7.1)

Description

MDaemon Mail Server 23.5.2 validates SPF, DKIM, and DMARC using the email enclosed in angle brackets (<>) in the From: header of SMTP DATA. An attacker can craft a From: header with multiple invisible Unicode thin spaces to display a spoofed sender while passing validation, allowing email spoofing even when anti-spoofing protections are in place. NOTE: this is disputed by the Supplier because UI spoofing occurs in a client, not in a server such as MDaemon's product or any other server implementation. Also, if a client without its own spoofing protection must be used, the Header Screening feature in MDaemon's product can be employed to mitigate the client-side vulnerability.

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CVSS v3.1 Score

7.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

Weakness Type (CWE)

CWE-20 Improper Input Validation

CWE-116 CWE-116

References

Other References

https://github.com/x00nullbit/CVE-References/blob/main/CVE-2025-61084/README.md

Frequently Asked Questions

What is CVE-2025-61084? +

MDaemon Mail Server 23.5.2 validates SPF, DKIM, and DMARC using the email enclosed in angle brackets (<>) in the From: header of SMTP DATA. An attacker can craft a From: header with multiple invisible Unicode thin spaces to display a spoofed sender while passing validation, allowing email spoofing even when anti-spoofing protections are in place. NOTE: this is disputed by the Supplier because UI spoofing occurs in a client, not in a server such as MDaemon's product or any other server implementation. Also, if a client without its own spoofing protection must be used, the Header Screening feature in MDaemon's product can be employed to mitigate the client-side vulnerability. It has a CVSS v3.1 base score of 7.1 (HIGH).

How severe is CVE-2025-61084? +

CVE-2025-61084 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

How do I check if I'm vulnerable to CVE-2025-61084? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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