High severity · published Apr 28, 2025
CVE-2025-34491
GFI MailEssentials prior to version 21.8 is vulnerable to a .NET deserialization issue
8.8
CVSS
0.9%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.9% · higher than 61% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
Mailessentials · Gfi
before 21.8 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-34491
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-34491
Exploit
https://frycos.github.io/vulns4free/2025/04/28/mailessentials.html
Release Notes
https://gfi.ai/products-and-solutions/network-security-solutions/mailessentials/resources/documentation/product-releases
www.vulncheck.com
https://www.vulncheck.com/advisories/gfi-mailessentials-multinode-insecure-deserialization
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