Remote Code Execution Vulnerability in GFI MailEssentials by GFI Software
CVE-2025-34491

8.8HIGH

Key Information:

Vendor

Gfi

Status
Mailessentials
Vendor
CVE Published:
28 April 2025

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2025-34491?

GFI MailEssentials prior to version 21.8 is susceptible to a serious vulnerability that stems from improper handling of .NET serialization. This issue enables a remote attacker, once authenticated, to execute arbitrary code by crafting malicious serialized data when connecting to a Multi-Server setup. The exploitation of this vulnerability could lead to unauthorized access and potential manipulation of the compromised system. Users of GFI MailEssentials are strongly advised to upgrade to the latest version to mitigate this risk.

Affected Version(s)

MailEssentials 0 < 21.8

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2025-34491 - Proof of Concept

References

https://frycos.github.io/vulns4free/2025/04/28/mailessent...
technical-descriptionexploit
https://gfi.ai/products-and-solutions/network-security-so...
vendor-advisory
https://www.vulncheck.com/advisories/gfi-mailessentials-m...
third-party-advisory

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Frycos
JSON
.