Cisco IOS and IOS XE Software AAA Login Denial of Service Vulnerability

A vulnerability in the Authentication, Authorization, and Accounting (AAA) service for remote Secure Shell Host (SSH) connections to the device for Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to cause the vulnerable device to reload.

The vulnerability is due to an error log message when a remote SSH connection to the device fails AAA authentication. An attacker could exploit this vulnerability by attempting to authenticate to the targeted device. An exploit could allow the attacker to cause a denial of service (DoS) condition.

Cisco has released software updates that address this vulnerability. There is a workaround that addresses this vulnerability.

This advisory is available at the following link:

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160928-aaados[“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160928-aaados”]

This advisory is part of the September 28, 2016, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes 10 Cisco Security Advisories that describe 11 vulnerabilities. All the vulnerabilities have a Security Impact Rating of “High.” For a complete list of the advisories and links to them, see Cisco Event Response: September 2016 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication[“https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-56513”].