---
id: CVE-2020-3315
title: >-
  Multiple Cisco products are affected by a vulnerability in the Snort detection
  engine that could allow an unauthenticated, remote attacker to bypass the
  configured file policies on an affected system
summary: >-
  Multiple Cisco products are affected by a vulnerability in the Snort detection
  engine that could allow an unauthenticated, remote attacker to bypass the
  configured file policies on an affected system. The vulnerability is due to
  errors i…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'
cwe:
  - CWE-693
  - CWE-668
vendor: cisco
product: secure_firewall_management_center
affected:
  - secure_firewall_management_center = 2.9.14.4
  - secure_firewall_management_center = 2.9.15
  - secure_firewall_management_center = 2.9.16
  - secure_firewall_threat_defense < 6.6.0
  - ios = 15.2(7)e
  - ios = 16.11.2
  - ios = 17.3.1
patched:
  - secure_firewall_threat_defense 6.6.0
published: '2020-05-06'
updated: '2026-08-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-3315'
references:
  - url: 'https://lists.debian.org/debian-lts-announce/2023/02/msg00011.html'
    label: psirt@cisco.com
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort_filepolbypass-m4X5DgOP
    label: psirt@cisco.com
  - url: 'https://www.debian.org/security/2023/dsa-5354'
    label: psirt@cisco.com
  - url: 'https://lists.debian.org/debian-lts-announce/2023/02/msg00011.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort_filepolbypass-m4X5DgOP
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.debian.org/security/2023/dsa-5354'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.0221
epssPercentile: 0.81618
ingestedAt: '2026-08-11T19:48:28.213Z'
---

## Overview

Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could allow an unauthenticated, remote attacker to bypass the configured file policies on an affected system. The vulnerability is due to errors in how the Snort detection engine handles specific HTTP responses. An attacker could exploit this vulnerability by sending crafted HTTP packets that would flow through an affected system. A successful exploit could allow the attacker to bypass the configured file policies and deliver a malicious payload to the protected network.

## Affected

- `secure_firewall_management_center = 2.9.14.4`
- `secure_firewall_management_center = 2.9.15`
- `secure_firewall_management_center = 2.9.16`
- `secure_firewall_threat_defense < 6.6.0`
- `ios = 15.2(7)e`
- `ios = 16.11.2`
- `ios = 17.3.1`

## Remediation

Upgrade past the affected range:

- `secure_firewall_threat_defense 6.6.0`