CVE-2025-61084

HIGHCVSS 7.1/10EPSS 0.20%

Last modified

CVE-2025-61084 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. 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. EPSS estimates a 0.20% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
7.1/10

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

EPSS Probability
0.20%

9.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published
Last Modified
Status
Deferred

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.
How severe is CVE-2025-61084?
CVE-2025-61084 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 0.20% probability of exploitation in the next 30 days.
How do I fix CVE-2025-61084?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-61084?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST