// For flags

CVE-2020-3421

Cisco IOS XE Software Zone-Based Firewall Denial of Service Vulnerabilities

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Attend
*SSVC
Descriptions

Multiple vulnerabilities in the Zone-Based Firewall feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload or stop forwarding traffic through the firewall. The vulnerabilities are due to incomplete handling of Layer 4 packets through the device. An attacker could exploit these vulnerabilities by sending a certain sequence of traffic patterns through the device. A successful exploit could allow the attacker to cause the device to reload or stop forwarding traffic through the firewall, resulting in a denial of service. For more information about these vulnerabilities, see the Details section of this advisory.

Múltiples vulnerabilidades en la funcionalidad Zone-Based Firewall de Cisco IOS XE Software, podrían permitir a un atacante remoto no autenticado causar que el dispositivo se recargue o deje de reenviar tráfico por medio del firewall. Las vulnerabilidades son debido al manejo incompleto de los paquetes de Capa 4 a través del dispositivo. Un atacante podría explotar estas vulnerabilidades mediante el envío de una determinada secuencia de patrones de tráfico a través del dispositivo. Una explotación con éxito podría permitir al atacante causar que el dispositivo se recargue o deje de reenviar tráfico por medio del firewall, resultando en una denegación de servicio. Para más información sobre estas vulnerabilidades, consulte la sección Detalles de este aviso.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:Attend
Exploitation
None
Automatable
Yes
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2019-12-12 CVE Reserved
  • 2020-09-24 CVE Published
  • 2023-06-10 EPSS Updated
  • 2024-11-13 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-754: Improper Check for Unusual or Exceptional Conditions
CAPEC
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"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
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"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
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"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
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"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
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"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
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"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
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"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1001-hx
Search vendor "Cisco" for product "Asr 1001-hx"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1001-x
Search vendor "Cisco" for product "Asr 1001-x"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1002-hx
Search vendor "Cisco" for product "Asr 1002-hx"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1002-x
Search vendor "Cisco" for product "Asr 1002-x"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1004
Search vendor "Cisco" for product "Asr 1004"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1006
Search vendor "Cisco" for product "Asr 1006"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1006-x
Search vendor "Cisco" for product "Asr 1006-x"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1009-x
Search vendor "Cisco" for product "Asr 1009-x"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
16.9.3
Search vendor "Cisco" for product "Ios Xe" and version "16.9.3"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1013
Search vendor "Cisco" for product "Asr 1013"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
1100 Integrated Services Router
Search vendor "Cisco" for product "1100 Integrated Services Router"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
1101 Integrated Services Router
Search vendor "Cisco" for product "1101 Integrated Services Router"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
1109 Integrated Services Router
Search vendor "Cisco" for product "1109 Integrated Services Router"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
1111x Integrated Services Router
Search vendor "Cisco" for product "1111x Integrated Services Router"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
111x Integrated Services Router
Search vendor "Cisco" for product "111x Integrated Services Router"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
1120 Integrated Services Router
Search vendor "Cisco" for product "1120 Integrated Services Router"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
1160 Integrated Services Router
Search vendor "Cisco" for product "1160 Integrated Services Router"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
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"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
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"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
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"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
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"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1001-hx
Search vendor "Cisco" for product "Asr 1001-hx"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1001-x
Search vendor "Cisco" for product "Asr 1001-x"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1002-hx
Search vendor "Cisco" for product "Asr 1002-hx"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1002-x
Search vendor "Cisco" for product "Asr 1002-x"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1004
Search vendor "Cisco" for product "Asr 1004"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1006
Search vendor "Cisco" for product "Asr 1006"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1006-x
Search vendor "Cisco" for product "Asr 1006-x"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1009-x
Search vendor "Cisco" for product "Asr 1009-x"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
Asr 1013
Search vendor "Cisco" for product "Asr 1013"
--
Safe
Cisco
Search vendor "Cisco"
Ios Xe
Search vendor "Cisco" for product "Ios Xe"
17.2
Search vendor "Cisco" for product "Ios Xe" and version "17.2"
-
Affected
in Cisco
Search vendor "Cisco"
Csr 1000v
Search vendor "Cisco" for product "Csr 1000v"
--
Safe