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Fortios CVE-2023-42786

MEDIUM
NULL Pointer Dereference (CWE-476)
2025-01-14 psirt@fortinet.com
6.5
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A10:2025 - Mishandling of Exceptional Conditions
ASVS 5.0
V16 - Security Logging and Error Handling Null pointer safety, defensive checks
MITRE ATT&CK

1 technique across 1 tactic: Impact

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 6.5 (MEDIUM). Attack characteristics: network attack vector, low complexity, low privileges required, no user interaction not required. EPSS exploitation probability: 0.66%.

Exploit ScenarioDerived

A remote attacker could crash the application by dereferencing a null pointer by sending crafted requests to the affected application.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
No patch listed yet 0.7% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 28, 2026

A null pointer dereference in FortiOS versions 7.4.0 through 7.4.1, 7.2.0 through 7.2.5, 7.0 all versions, 6.4 all versions , 6.2 all versions and 6.0 all versions allows attacker to trigger a denial. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Earlier versions of this analysis (1)
v1 Mar 28, 2026 - 18:03 CVSS 6.5

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Check pointers before dereferencing. Use static analysis tools to detect null pointer paths.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as NULL Pointer Dereference (CWE-476), which allows attackers to crash the application by dereferencing a null pointer. A null pointer dereference in FortiOS versions 7.4.0 through 7.4.1, 7.2.0 through 7.2.5, 7.0 all versions, 6.4 all versions , 6.2 all versions and 6.0 all versions allows attacker to trigger a denial of service via a crafted http request. Affected products include: Fortinet Fortios. Version information: through 7.4.1.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 6.5 MEDIUM
AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionCVE.org

A null pointer dereference in FortiOS versions 7.4.0 through 7.4.1, 7.2.0 through 7.2.5, 7.0 all versions, 6.4 all versions , 6.2 all versions and 6.0 all versions allows attacker to trigger a denial of service via a crafted http request.

Executive ViewAI

Why It Matters

Organizations using FortiOS should be aware of notable risk from CVE-2023-42786, a null pointer dereference vulnerability rated CVSS 6.5. Exploitation could compromise the security of affected deployments. Organizations should apply vendor updates when available and monitor for exploitation.

Business Impact: Moderate
Compensating Controls

Apply vendor patch. If patching is delayed: enable ASLR/DEP, apply network segmentation.

Threat Intelligence Overview

EPSS Score
0.7%
Top 29% exploitable
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.7%
Patch available No
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No

Priority Score

33
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +32
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A null pointer dereference occurs when a program attempts to access memory through a pointer that has been set to NULL (address 0x0).

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)CVE.org

cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
CVE-2022-40684 CRITICAL POC
9.8 Oct 18

An authentication bypass using an alternate path or channel [CWE-288] in Fortinet FortiOS version 7.2.0 through 7.2.1 an

CVE-2024-55591 CRITICAL POC
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FortiOS and FortiProxy contain an authentication bypass via the Node.js websocket module allowing unauthenticated remote

CVE-2024-21762 CRITICAL POC
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A out-of-bounds write in Fortinet FortiOS versions 7.4.0 through 7.4.2, 7.2.0 through 7.2.6, 7.0.0 through 7.0.13, 6.4.0

CVE-2023-27997 CRITICAL
9.8 Jun 13

A heap-based buffer overflow vulnerability [CWE-122] in FortiOS version 7.2.4 and below, version 7.0.11 and below, versi

CVE-2020-12812 CRITICAL
9.8 Jul 24

FortiOS SSL-VPN contains an improper authentication vulnerability that allows users to bypass two-factor authentication

CVE-2016-1909 CRITICAL POC
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Fortinet FortiAnalyzer before 5.0.12 and 5.2.x before 5.2.5; FortiSwitch 3.3.x before 3.3.3; FortiCache 3.0.x before 3.0

CVE-2016-6909 CRITICAL POC
9.8 Aug 24

Buffer overflow in the Cookie parser in Fortinet FortiOS 4.x before 4.1.11, 4.2.x before 4.2.13, and 4.3.x before 4.3.9

CVE-2025-25249 CRITICAL POC
9.8 Jan 13

Remote code execution in Fortinet FortiOS (6.4 through 7.6.3) and FortiSwitchManager (7.0.x/7.2.x) lets an attacker run

CVE-2025-61624 MEDIUM POC
6.5 Apr 14

Path traversal vulnerability in Fortinet FortiOS, FortiProxy, FortiPAM, and FortiSwitchManager allows authenticated admi

CVE-2015-1880 MEDIUM POC
4.3 May 12

Cross-site scripting (XSS) vulnerability in the sslvpn login page in Fortinet FortiOS 5.2.x before 5.2.3 allows remote a

CVE-2025-24472 HIGH
8.1 Feb 11

FortiOS and FortiProxy contain an authentication bypass allowing unauthenticated attackers with knowledge of upstream/do

CVE-2025-68686 MEDIUM POC
5.9 Feb 10

An Exposure of Sensitive Information to an Unauthorized Actor vulnerability [CWE-200] vulnerability in Fortinet FortiOS

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