CVE-2021-34698

Cisco Web Security Appliance Proxy Service Denial of Service Vulnerability

Severity Score

7.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Attend

*SSVC

Descriptions

A vulnerability in the proxy service of Cisco AsyncOS for Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to exhaust system memory and cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper memory management in the proxy service of an affected device. An attacker could exploit this vulnerability by establishing a large number of HTTPS connections to the affected device. A successful exploit could allow the attacker to cause the system to stop processing new connections, which could result in a DoS condition. Note: Manual intervention may be required to recover from this situation.

Una vulnerabilidad en el servicio proxy de Cisco AsyncOS para Cisco Web Security Appliance (WSA) podría permitir a un atacante remoto no autenticado agotar la memoria del sistema y causar una condición de denegación de servicio (DoS) en un dispositivo afectado. Esta vulnerabilidad es debido a una administración inapropiada de la memoria en el servicio proxy de un dispositivo afectado. Un atacante podría explotar esta vulnerabilidad al establecer un gran número de conexiones HTTPS al dispositivo afectado. Una explotación con éxito podría permitir al atacante causar que el sistema deje de procesar nuevas conexiones, lo que podría resultar en una condición de DoS. Nota: Puede ser necesaria una intervención manual para recuperarse de esta situación

*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

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:Attend

Exploitation

None

Automatable

Yes

Tech. Impact

Total

* Organization's Worst-case Scenario

Timeline

2021-06-15 CVE Reserved
2021-10-06 CVE Published
2024-06-21 EPSS Updated
2024-11-07 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-401: Missing Release of Memory after Effective Lifetime

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-wsa-dos-fmHdKswk	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"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.0 < 12.0.3-005 Search vendor "Cisco" for product "Asyncos" and version " >= 12.0 < 12.0.3-005"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S170 Search vendor "Cisco" for product "Web Security Appliance S170"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.0 < 12.0.3-005 Search vendor "Cisco" for product "Asyncos" and version " >= 12.0 < 12.0.3-005"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S190 Search vendor "Cisco" for product "Web Security Appliance S190"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.0 < 12.0.3-005 Search vendor "Cisco" for product "Asyncos" and version " >= 12.0 < 12.0.3-005"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S380 Search vendor "Cisco" for product "Web Security Appliance S380"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.0 < 12.0.3-005 Search vendor "Cisco" for product "Asyncos" and version " >= 12.0 < 12.0.3-005"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S390 Search vendor "Cisco" for product "Web Security Appliance S390"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.0 < 12.0.3-005 Search vendor "Cisco" for product "Asyncos" and version " >= 12.0 < 12.0.3-005"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S680 Search vendor "Cisco" for product "Web Security Appliance S680"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.0 < 12.0.3-005 Search vendor "Cisco" for product "Asyncos" and version " >= 12.0 < 12.0.3-005"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S690 Search vendor "Cisco" for product "Web Security Appliance S690"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.0 < 12.0.3-005 Search vendor "Cisco" for product "Asyncos" and version " >= 12.0 < 12.0.3-005"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S690x Search vendor "Cisco" for product "Web Security Appliance S690x"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.5 < 12.5.2-007 Search vendor "Cisco" for product "Asyncos" and version " >= 12.5 < 12.5.2-007"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S170 Search vendor "Cisco" for product "Web Security Appliance S170"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.5 < 12.5.2-007 Search vendor "Cisco" for product "Asyncos" and version " >= 12.5 < 12.5.2-007"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S190 Search vendor "Cisco" for product "Web Security Appliance S190"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.5 < 12.5.2-007 Search vendor "Cisco" for product "Asyncos" and version " >= 12.5 < 12.5.2-007"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S380 Search vendor "Cisco" for product "Web Security Appliance S380"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.5 < 12.5.2-007 Search vendor "Cisco" for product "Asyncos" and version " >= 12.5 < 12.5.2-007"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S390 Search vendor "Cisco" for product "Web Security Appliance S390"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.5 < 12.5.2-007 Search vendor "Cisco" for product "Asyncos" and version " >= 12.5 < 12.5.2-007"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S680 Search vendor "Cisco" for product "Web Security Appliance S680"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.5 < 12.5.2-007 Search vendor "Cisco" for product "Asyncos" and version " >= 12.5 < 12.5.2-007"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S690 Search vendor "Cisco" for product "Web Security Appliance S690"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 12.5 < 12.5.2-007 Search vendor "Cisco" for product "Asyncos" and version " >= 12.5 < 12.5.2-007"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S690x Search vendor "Cisco" for product "Web Security Appliance S690x"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 14.0 < 14.0.1-014 Search vendor "Cisco" for product "Asyncos" and version " >= 14.0 < 14.0.1-014"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S170 Search vendor "Cisco" for product "Web Security Appliance S170"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 14.0 < 14.0.1-014 Search vendor "Cisco" for product "Asyncos" and version " >= 14.0 < 14.0.1-014"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S190 Search vendor "Cisco" for product "Web Security Appliance S190"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 14.0 < 14.0.1-014 Search vendor "Cisco" for product "Asyncos" and version " >= 14.0 < 14.0.1-014"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S380 Search vendor "Cisco" for product "Web Security Appliance S380"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 14.0 < 14.0.1-014 Search vendor "Cisco" for product "Asyncos" and version " >= 14.0 < 14.0.1-014"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S390 Search vendor "Cisco" for product "Web Security Appliance S390"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 14.0 < 14.0.1-014 Search vendor "Cisco" for product "Asyncos" and version " >= 14.0 < 14.0.1-014"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S680 Search vendor "Cisco" for product "Web Security Appliance S680"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 14.0 < 14.0.1-014 Search vendor "Cisco" for product "Asyncos" and version " >= 14.0 < 14.0.1-014"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S690 Search vendor "Cisco" for product "Web Security Appliance S690"	-	-	Safe
Cisco Search vendor "Cisco"	Asyncos Search vendor "Cisco" for product "Asyncos"	>= 14.0 < 14.0.1-014 Search vendor "Cisco" for product "Asyncos" and version " >= 14.0 < 14.0.1-014"	-	Affected	in	Cisco Search vendor "Cisco"	Web Security Appliance S690x Search vendor "Cisco" for product "Web Security Appliance S690x"	-	-	Safe