CVE-2021-1236: Multiple Cisco Products Snort Application Detection Engine Policy Bypass Vulnerability

Published Jan 13, 2021
·
Updated

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

Affected Software

45 affected componentsFixes available
debian/snort<=2.9.7.0-5, <=2.9.15.1-5
2.9.20-0+deb10u12.9.20-0+deb11u12.9.15.1-6
Cisco IOS XE<17.4.1
Cisco 1100-4p Integrated Services Router
Cisco 1100-8p Integrated Services Router
Cisco 1101-4p Integrated Services Router
Cisco 1109-2p Integrated Services Router
Cisco 1109-4p Integrated Services Router
Cisco 1111x-8p Integrated Services Router
Cisco 4221 Integrated Services Router
Cisco 4321 Integrated Services Router
Cisco 4331 Integrated Services Router
Cisco 4351 Integrated Services Router
Cisco 4431 Integrated Services Router
Cisco 4451-x Integrated Services Router
Cisco 4461 Integrated Services Router
Cisco Csr 1000v
Cisco Isa 3000
Cisco FirePOWER Management Center=2.9.14.0
Cisco FirePOWER Management Center=2.9.14.14
Cisco FirePOWER Management Center=2.9.15
Cisco FirePOWER Management Center=2.9.16
Cisco FirePOWER Management Center=2.9.17
Cisco Firepower Threat Defense<6.5.0.5
Snort Snort<2.9.14
All of the following
Cisco IOS XE<17.4.1
Any of the following
Cisco 1100-4p Integrated Services Router
Cisco 1100-8p Integrated Services Router
Cisco 1101-4p Integrated Services Router
Cisco 1109-2p Integrated Services Router
Cisco 1109-4p Integrated Services Router
Cisco 1111x-8p Integrated Services Router
Cisco 4221 Integrated Services Router
Cisco 4321 Integrated Services Router
Cisco 4331 Integrated Services Router
Cisco 4351 Integrated Services Router
Cisco 4431 Integrated Services Router
Cisco 4451-x Integrated Services Router
Cisco 4461 Integrated Services Router
Cisco Csr 1000v
Cisco Isa 3000
Cisco Secure Firewall Management Center=2.9.14.0
Cisco Secure Firewall Management Center=2.9.14.14
Cisco Secure Firewall Management Center=2.9.15
Cisco Secure Firewall Management Center=2.9.16
Cisco Secure Firewall Management Center=2.9.17

Event History

Jan 13, 2021
CVE Published
via MITRE·09:17 PM
Data Sourced
via MITRE·09:17 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·10:15 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the vulnerability ID of this security issue?

The vulnerability ID is CVE-2021-1236.

2

Which products are affected by this vulnerability?

Multiple Cisco products including Cisco IOS XE and Cisco Firepower Management Center are affected.

3

What is the severity of CVE-2021-1236?

The severity of CVE-2021-1236 is medium with a CVSS score of 5.3.

4

How can an attacker exploit CVE-2021-1236?

An attacker can exploit CVE-2021-1236 by bypassing the configured policies on an affected system.

5

How can I fix CVE-2021-1236?

To fix CVE-2021-1236, update the affected Cisco products with the appropriate security patches.

Contact

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