Vulnerability · Published Apr 28, 2025 · Assigned by VulnCheck
CVE-2025-34491GFI MailEssentials < 21.8 MultiNode Insecure Deserialization
High 8.8
In plain English
A high-severity unsafe deserialization in MailEssentials from GFI. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 62% of all known vulnerabilities).
Severity (CVSS 3.1)8.8High
Exploit odds (30 days)1.0%top 38.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| GFI | MailEssentials | 0 – before 21.8 |
Weakness: CWE-502 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
- https://frycos.github.io/vulns4free/2025/04/28/mailessentials.html technical-description, exploit
- https://gfi.ai/products-and-solutions/network-security-solutions/mailessentials/resources/documentation/product-releases vendor-advisory
- https://www.vulncheck.com/advisories/gfi-mailessentials-multinode-insecure-deserialization third-party-advisory