CVE-2021-1236

Multiple Cisco Products Snort Application Detection Engine Policy Bypass Vulnerability

Severity Score

5.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

Múltiples productos de Cisco están afectados por una vulnerabilidad en el motor de detección de aplicaciones de Snort que podría permitir a un atacante remoto no autenticado omitir las políticas configuradas en un sistema afectado. La vulnerabilidad es debido a un fallo en el algoritmo de detección. Un atacante podría explotar esta vulnerabilidad mediante el envío de paquetes diseñados que fluirían a través de un sistema afectado. Una explotación con éxito podría permitir al atacante omitir las políticas configuradas y entregar una carga útil maliciosa a la red protegida.

*Credits: N/A

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

Low

Availability

None

Attack Vector

Network

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-11-13 CVE Reserved
2021-01-13 CVE Published
2023-09-29 EPSS Updated
2024-09-16 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-670: Always-Incorrect Control Flow Implementation

CAPEC

References (3)

URL	Tag	Source
https://lists.debian.org/debian-lts-announce/2023/02/msg00011.html	Mailing List

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort-app-bypass-cSBYCATq	2023-05-22
https://www.debian.org/security/2023/dsa-5354	2023-05-22

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	1100-4p Integrated Services Router Search vendor "Cisco" for product "1100-4p Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	1100-8p Integrated Services Router Search vendor "Cisco" for product "1100-8p Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	1101-4p Integrated Services Router Search vendor "Cisco" for product "1101-4p Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	1109-2p Integrated Services Router Search vendor "Cisco" for product "1109-2p Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	1109-4p Integrated Services Router Search vendor "Cisco" for product "1109-4p Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	1111x-8p Integrated Services Router Search vendor "Cisco" for product "1111x-8p Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	4221 Integrated Services Router Search vendor "Cisco" for product "4221 Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	4321 Integrated Services Router Search vendor "Cisco" for product "4321 Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	4331 Integrated Services Router Search vendor "Cisco" for product "4331 Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	4351 Integrated Services Router Search vendor "Cisco" for product "4351 Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	4431 Integrated Services Router Search vendor "Cisco" for product "4431 Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	4451-x Integrated Services Router Search vendor "Cisco" for product "4451-x Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	4461 Integrated Services Router Search vendor "Cisco" for product "4461 Integrated Services Router"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	Csr 1000v Search vendor "Cisco" for product "Csr 1000v"	-	-	Safe
Cisco Search vendor "Cisco"	Ios Xe Search vendor "Cisco" for product "Ios Xe"	< 17.4.1 Search vendor "Cisco" for product "Ios Xe" and version " < 17.4.1"	-	Affected	in	Cisco Search vendor "Cisco"	Isa 3000 Search vendor "Cisco" for product "Isa 3000"	-	-	Safe
Cisco Search vendor "Cisco"		Firepower Management Center Search vendor "Cisco" for product "Firepower Management Center"				2.9.14.0 Search vendor "Cisco" for product "Firepower Management Center" and version "2.9.14.0"		-		Affected
Cisco Search vendor "Cisco"		Firepower Management Center Search vendor "Cisco" for product "Firepower Management Center"				2.9.14.14 Search vendor "Cisco" for product "Firepower Management Center" and version "2.9.14.14"		-		Affected
Cisco Search vendor "Cisco"		Firepower Management Center Search vendor "Cisco" for product "Firepower Management Center"				2.9.15 Search vendor "Cisco" for product "Firepower Management Center" and version "2.9.15"		-		Affected
Cisco Search vendor "Cisco"		Firepower Management Center Search vendor "Cisco" for product "Firepower Management Center"				2.9.16 Search vendor "Cisco" for product "Firepower Management Center" and version "2.9.16"		-		Affected
Cisco Search vendor "Cisco"		Firepower Management Center Search vendor "Cisco" for product "Firepower Management Center"				2.9.17 Search vendor "Cisco" for product "Firepower Management Center" and version "2.9.17"		-		Affected
Cisco Search vendor "Cisco"		Firepower Threat Defense Search vendor "Cisco" for product "Firepower Threat Defense"				< 6.5.0.5 Search vendor "Cisco" for product "Firepower Threat Defense" and version " < 6.5.0.5"		-		Affected
Snort Search vendor "Snort"		Snort Search vendor "Snort" for product "Snort"				< 2.9.14 Search vendor "Snort" for product "Snort" and version " < 2.9.14"		-		Affected