CVE-2021-1356

Cisco IOS XE Software Web UI Denial of Service Vulnerabilities

Severity Score

4.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

Multiple vulnerabilities in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker with read-only privileges to cause the web UI software to become unresponsive and consume vty line instances, resulting in a denial of service (DoS) condition. These vulnerabilities are due to insufficient error handling in the web UI. An attacker could exploit these vulnerabilities by sending crafted HTTP packets to an affected device. A successful exploit could allow the attacker to cause the web UI software to become unresponsive and consume all available vty lines, preventing new session establishment and resulting in a DoS condition. Manual intervention would be required to regain web UI and vty session functionality. Note: These vulnerabilities do not affect the console connection.

Múltiples vulnerabilidades en la Interfaz de Usuario Web del Software Cisco IOS XE, podrían permitir a un atacante remoto autenticado con privilegios de solo lectura causar que el software de la Interfaz de Usuario Web deje de responder y consuma instancias de línea vty, lo que resultará en una condición de denegación de servicio (DoS). Estas vulnerabilidades son debido a un manejo insuficiente de errores en la Interfaz de Usuario Web. Un atacante podría explotar estas vulnerabilidades mediante el envío de paquetes HTTP diseñados a un dispositivo afectado. Una explotación con éxito podría permitir que el atacante cause que el software de la Interfaz de Usuario Web dejara de responder y consumiera todas las líneas vty disponibles, impidiendo el establecimiento de una nueva sesión y dando como resultado una condición de DoS. Se necesitaría una intervención manual para recuperar la interfaz de usuario web y la funcionalidad de la sesión vty. Nota: estas vulnerabilidades no afectan la conexión de la consola

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Attack Vector

Network

Attack Complexity

Medium

Authentication

Single

Confidentiality

None

Integrity

None

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2020-11-13 CVE Reserved
2021-03-24 CVE Published
2024-06-25 EPSS Updated
2024-11-08 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-20: Improper Input Validation
CWE-755: Improper Handling of Exceptional Conditions

CAPEC

References (1)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xe-webui-dos-z9yqYQAn	2023-11-07

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"				3.15.1xbs Search vendor "Cisco" for product "Ios Xe" and version "3.15.1xbs"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				3.15.2xbs Search vendor "Cisco" for product "Ios Xe" and version "3.15.2xbs"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				17.1.1 Search vendor "Cisco" for product "Ios Xe" and version "17.1.1"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				17.1.1a Search vendor "Cisco" for product "Ios Xe" and version "17.1.1a"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				17.1.1s Search vendor "Cisco" for product "Ios Xe" and version "17.1.1s"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				17.1.1t Search vendor "Cisco" for product "Ios Xe" and version "17.1.1t"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				17.1.2 Search vendor "Cisco" for product "Ios Xe" and version "17.1.2"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				17.2.1 Search vendor "Cisco" for product "Ios Xe" and version "17.2.1"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				17.2.1a Search vendor "Cisco" for product "Ios Xe" and version "17.2.1a"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				17.2.1r Search vendor "Cisco" for product "Ios Xe" and version "17.2.1r"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				17.2.1v Search vendor "Cisco" for product "Ios Xe" and version "17.2.1v"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				17.2.2 Search vendor "Cisco" for product "Ios Xe" and version "17.2.2"		-		Affected
Cisco Search vendor "Cisco"		Ios Xe Search vendor "Cisco" for product "Ios Xe"				17.2.3 Search vendor "Cisco" for product "Ios Xe" and version "17.2.3"		-		Affected