CVE-2021-1359: A vulnerability in the configuration management of Cisco AsyncOS for Cisco Web Security Appliance (WSA) could allow an authenticated, remote attacker ...

Description

A vulnerability in the configuration management of Cisco AsyncOS for Cisco Web Security Appliance (WSA) could allow an authenticated, remote attacker to perform command injection and elevate privileges to root. This vulnerability is due to insufficient validation of user-supplied XML input for the web interface. An attacker could exploit this vulnerability by uploading crafted XML configuration files that contain scripting code to a vulnerable device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system and elevate privileges to root. An attacker would need a valid user account with the rights to upload configuration files to exploit this vulnerability.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.88%

76.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-112

Affected Software

Vendor	Product	Versions
Cisco	Web Security Appliance	11.8.0-429
Cisco	Web Security Appliance	11.8.0-453
Cisco	Asyncos	>= 11.8.0, < 12.0.3-005
Cisco	Asyncos	>= 12.5.0, < 12.5.2

References

Timeline

Published: Jul 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-1359?

A vulnerability in the configuration management of Cisco AsyncOS for Cisco Web Security Appliance (WSA) could allow an authenticated, remote attacker to perform command injection and elevate privileges to root. This vulnerability is due to insufficient validation of user-supplied XML input for the web interface. An attacker could exploit this vulnerability by uploading crafted XML configuration files that contain scripting code to a vulnerable device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system and elevate privileges to root. An attacker would need a valid user account with the rights to upload configuration files to exploit this vulnerability.

How severe is CVE-2021-1359?

CVE-2021-1359 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.88% probability of exploitation in the next 30 days.

How do I fix CVE-2021-1359?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.