CyberSecBulletin
CVE-2025-46373NVD status: Modified

FortiClientWindows: Heap-based Buffer Overflow

Published Updated By the CyberSecBulletin desk

CVE-2025-46373 is a high-severity heap-based buffer overflow vulnerability in FortiClientWindows from Fortinet, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected FortiClientWindows versions: 7.4.0 through 7.4.3; 7.2.0 through 7.2.8. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.16% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Forticlient to 7.2.9 or 7.4.4, whichever matches your release line, or a later version.
  2. Read the advisory on fortiguard.fortinet.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
FortinetFortiClientWindows7.4.0 through 7.4.3; 7.2.0 through 7.2.8Not stated
FortinetForticlient7.2.0 up to, but not including, 7.2.9; 7.4.0 up to, but not including, 7.4.47.2.9, 7.4.4

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (fortinet.com).

Official description

A Heap-based Buffer Overflow vulnerability [CWE-122] vulnerability in Fortinet FortiClientWindows 7.4.0 through 7.4.3, FortiClientWindows 7.2.0 through 7.2.8 may allow an authenticated local IPSec user to execute arbitrary code or commands via "fortips_74.sys". The attacker would need to bypass the Windows heap integrity protections

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Heap-based Buffer Overflow

The product writes past the end of a buffer that was allocated on the heap.

How developers prevent this class of flaw

  • Pre-design: Use a language or compiler that performs automatic bounds checking.
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Heap-based Buffer Overflow vulnerabilities (CWE-122)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in FortiClientWindows

All FortiClientWindows vulnerabilities

Recent Heap-based Buffer Overflow vulnerabilities

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