Home/CVE/GFI MailEssentials prior to version 21.8 is vulnerable to a .NET deserialization issue. A remote and authenticated attac
CVE

CVE-2025-34491

GFI MailEssentials prior to version 21.8 is vulnerable to a .NET deserialization issue. A remote and authenticated attac

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.

HIGH · CVSS 8.8 EPSS 0.01157
Act now
  • Public exploit or PoC is available
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-502Deserialization of Untrusted Data
CWE-502Deserialization of Untrusted Data
▤

Affected Products & Versions

1
gfi mailessentials< 21.8
⚠

Public Exploits & PoCs

1
pocfrycos.github.io · mailessentials.htmlfrycos.github.io
▣

Scoring & Timeline

8.8
HIGH · CVSS v3.1 · disclosure@vulncheck.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD28 Apr 2025 · 08:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
SSVC triage · cisa-vulnrichment
Exploitation
poc
Automatable
no
Technical impact
total
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://gfi.ai/products-and-solutions/network-security-solutions/mailessentials/resources/documentation/product-releasesRelease Notes
https://www.vulncheck.com/advisories/gfi-mailessentials-multinode-insecure-deserialization
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