CVE-2018-13383

Name: CVE-2018-13383
Creator: NVD / NIST
Published: 2019-05-29T18:29:00.693+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10Actively ExploitedEPSS 33.65%

Last modified Jun 17, 2026

CVE-2018-13383 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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.. CISA has confirmed active exploitation in the wild. EPSS estimates a 33.65% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

33.65%

98.2th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Jul 10, 2022.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Fortinet	Fortiproxy	< 1.2.9
Fortinet	Fortiproxy	2.0.0
Fortinet	Fortios	>= 5.2.0, < 5.2.15
Fortinet	Fortios	>= 5.4.0, < 5.4.13
Fortinet	Fortios	>= 5.6.0, < 5.6.11
Fortinet	Fortios	>= 6.0.0, < 6.0.5

References

https://fortiguard.com/advisory/FG-IR-18-388Mitigation, Vendor Advisory
https://fortiguard.com/advisory/FG-IR-20-229Vendor Advisory
https://fortiguard.com/advisory/FG-IR-18-388Mitigation, Vendor Advisory
https://fortiguard.com/advisory/FG-IR-20-229Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-13383US Government Resource

Timeline

Published: May 29, 2019
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2018-13383?

How severe is CVE-2018-13383?

CVE-2018-13383 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 33.65% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2018-13383?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-13383?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST