CVE-2018-13383

Out-of-bounds Write

CVSS 3.1 Medium 4.3Known exploited (CISA KEV)

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Description

A heap buffer overflow in Fortinet FortiOS 6.0.0 through 6.0.4, 5.6.0 through 5.6.10, 5.4.0 through 5.4.12, 5.2.14 and earlier and FortiProxy 2.0.0, 1.2.8 and earlier in the SSL VPN web portal may cause the SSL VPN web service termination for logged in users due to a failure to properly handle javascript href data when proxying webpages.

Key data

CVSS 3.1 Medium 4.3

Score published by fortinet in the CVE record.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: Low
A basic user account is needed.
User interaction: None
No action from any user is needed.
Scope: Unchanged
The impact stays within the vulnerable component.
Confidentiality impact: None
No effect on the secrecy of data.
Integrity impact: None
No effect on the trustworthiness of data.
Availability impact: Low
Limited effect on availability.

Metric	Value	What it means
Attack vector	Network	The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity	Low	No special conditions are needed. The attack can be repeated at will.
Privileges required	Low	A basic user account is needed.
User interaction	None	No action from any user is needed.
Scope	Unchanged	The impact stays within the vulnerable component.
Confidentiality impact	None	No effect on the secrecy of data.
Integrity impact	None	No effect on the trustworthiness of data.
Availability impact	Low	Limited effect on availability.

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at first.org/cvss.

EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score: 0.30670 (30.7% probability)
Percentile: 98.3%
Scores of: Nov 10, 2026
Model: v2026.06.15

CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.

Name in the catalog: Fortinet FortiOS and FortiProxy Out-of-bounds Write
Added to the catalog: Jan 10, 2022
Federal due date: Jul 10, 2022
Ransomware campaigns: Known use

CISA assessment as of Oct 23, 2024

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.

Exploitation: Recorded by CISA as active
Automatable: no
Technical impact: partial

Weakness (CWE)

CWE catalog version 5.0.

CWE-787Out-of-bounds Write

Affected products

Products listed in the CVE record, as the CNA published them.

Fortinet FortiOS and FortiProxy
- affected: FortiOS 6.0.0 through 6.0.4, 5.6.0 through 5.6.10, 5.4.0 through 5.4.12, 5.2.14 and earlier, FortiProxy 2.0.0, 1.2.8 and earlier

References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

Timeline

ID reservedJul 6, 2018
Record publishedMay 29, 2019
Added to CISA KEVJan 10, 2022
Record last updatedOct 21, 2025

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About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.

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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:33 UTC. Sources and licenses