CVE-2025-34491: mailessentials — Exploit

Description

GFI MailEssentials prior to version 21.8 is vulnerable to a .NET deserialization issue. A remote and authenticated attacker can execute arbitrary code by sending crafted serialized .NET when joining to a Multi-Server setup.

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CVSS v3.1 Score

8.8

HIGH

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

Weakness Type (CWE)

CWE-502 Deserialization of Untrusted Data

Affected Products

Vendor	Product	Versions
gfi	mailessentials	< 21.8

References

Exploits

https://frycos.github.io/vulns4free/2025/04/28/mailessentials.html

Other References

https://gfi.ai/products-and-solutions/network-security-solutions/mailessentials/resources/documentation/product-releases https://www.vulncheck.com/advisories/gfi-mailessentials-multinode-insecure-deserialization

Frequently Asked Questions

What is CVE-2025-34491? +

GFI MailEssentials prior to version 21.8 is vulnerable to a .NET deserialization issue. A remote and authenticated attacker can execute arbitrary code by sending crafted serialized .NET when joining to a Multi-Server setup. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2025-34491? +

CVE-2025-34491 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-34491? +

CVE-2025-34491 affects products from gfi, specifically: mailessentials. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-34491? +

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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