---
id: CVE-2021-1223
title: >-
  Multiple Cisco products are affected by a vulnerability in the Snort detection
  engine that could allow an unauthenticated, remote attacker to bypass a
  configured file policy for HTTP
summary: >-
  Multiple Cisco products are affected by a vulnerability in the Snort detection
  engine that could allow an unauthenticated, remote attacker to bypass a
  configured file policy for HTTP. The vulnerability is due to incorrect
  handling of an …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'
cwe:
  - CWE-693
vendor: cisco
product: secure_firewall_management_center
affected:
  - secure_firewall_management_center = 2.9.14.0
  - secure_firewall_management_center = 2.9.15
  - secure_firewall_management_center = 2.9.16
  - secure_firewall_threat_defense < 6.7.0
  - ios_xe < 17.4.1
  - snort < 2.9.17
patched:
  - secure_firewall_threat_defense 6.7.0
  - ios_xe 17.4.1
  - snort 2.9.17
published: '2021-01-13'
updated: '2026-08-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-1223'
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-67DEwMe2
    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-67DEwMe2
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.debian.org/security/2023/dsa-5354'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.01985
epssPercentile: 0.79717
ingestedAt: '2026-08-18T12:28:06.756Z'
---

## Overview

Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP. The vulnerability is due to incorrect handling of an HTTP range header. An attacker could exploit this vulnerability by sending crafted HTTP packets through an affected device. A successful exploit could allow the attacker to bypass configured file policy for HTTP packets and deliver a malicious payload.

## Affected

- `secure_firewall_management_center = 2.9.14.0`
- `secure_firewall_management_center = 2.9.15`
- `secure_firewall_management_center = 2.9.16`
- `secure_firewall_threat_defense < 6.7.0`
- `ios_xe < 17.4.1`
- `snort < 2.9.17`

## Remediation

Upgrade past the affected range:

- `secure_firewall_threat_defense 6.7.0`
- `ios_xe 17.4.1`
- `snort 2.9.17`