---
id: CVE-2018-15390
title: >-
  A vulnerability in the FTP inspection engine of Cisco Firepower Threat Defense
  (FTD) Software could allow an unauthenticated, remote attacker to cause an
  affected device to reload, resulting in a denial of service (DoS) condition
summary: >-
  A vulnerability in the FTP inspection engine of Cisco Firepower Threat Defense
  (FTD) Software could allow an unauthenticated, remote attacker to cause an
  affected device to reload, resulting in a denial of service (DoS) condition.
  The vu…
severity: medium
cvss: 6.8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H'
cwe:
  - CWE-399
  - CWE-667
vendor: cisco
product: secure_firewall_threat_defense
affected:
  - 'secure_firewall_threat_defense >= 6.2.3.0, <= 6.2.3.4'
published: '2018-10-05'
updated: '2026-08-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2018-15390'
references:
  - url: 'http://www.securityfocus.com/bid/105519'
    label: psirt@cisco.com
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181003-ftd-inspect-dos
    label: psirt@cisco.com
  - url: 'http://www.securityfocus.com/bid/105519'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181003-ftd-inspect-dos
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.0112
epssPercentile: 0.64753
ingestedAt: '2026-08-11T19:48:25.877Z'
---

## Overview

A vulnerability in the FTP inspection engine of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software fails to release spinlocks when a device is running low on system memory, if the software is configured to apply FTP inspection and an access control rule to transit traffic, and the access control rule is associated with an FTP file policy. An attacker could exploit this vulnerability by sending a high rate of transit traffic through an affected device to cause a low-memory condition on the device. A successful exploit could allow the attacker to cause a software panic on the affected device, which could cause the device to reload and result in a temporary DoS condition.

## Affected

- `secure_firewall_threat_defense >= 6.2.3.0, <= 6.2.3.4`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.