CVE-2021-1619: Cisco IOS XE

Critical severity, CVSS 9.1. EPSS: 1.8% chance of exploitation in the next 30 days.

A vulnerability in the authentication, authorization, and accounting (AAA) function of Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass NETCONF or RESTCONF authentication and do either of the following: Install, manipulate, or delete the configuration of an affected device Cause memory corruption that results in a denial of service (DoS) on an affected device This vulnerability is due to an uninitialized variable. An attacker could exploit this vulnerability by sending a series of NETCONF or RESTCONF requests to an affected device. A successful exploit could allow the attacker to use NETCONF or RESTCONF to install, manipulate, or delete the configuration of a network device or to corrupt memory on the device, resulting a DoS.

Affected products

Cisco IOS XE: version 16.3.1 only; version 16.3.1a only; version 16.3.2 only; version 16.3.3 only; version 16.3.4 only; version 16.3.5 only; …
Cisco IOS XE SD-WAN: any version
Cisco IOS XE SD-WAN 16.10.1 When Installed On 1000 Series Integrated Services: version routers only
Cisco IOS XE SD-WAN 16.10.1 When Installed On 4000 Series Integrated Services: version routers only
Cisco IOS XE SD-WAN 16.10.1 When Installed On Asr 1000 Series Aggregation Services: version routers only
Cisco IOS XE SD-WAN 16.10.1 When Installed On Integrated Services Virtual: version router only
Cisco IOS XE SD-WAN 16.10.2 When Installed On 1000 Series Integrated Services: version routers only
Cisco IOS XE SD-WAN 16.10.2 When Installed On 4000 Series Integrated Services: version routers only
Cisco IOS XE SD-WAN 16.10.2 When Installed On Asr 1000 Series Aggregation Services: version routers only
Cisco IOS XE SD-WAN 16.10.2 When Installed On Integrated Services Virtual: version router only
Cisco IOS XE SD-WAN 16.10.3 When Installed On 1000 Series Integrated Services: version routers only
Cisco IOS XE SD-WAN 16.10.3 When Installed On 4000 Series Integrated Services: version routers only
Cisco IOS XE SD-WAN 16.10.3 When Installed On Asr 1000 Series Aggregation Services: version routers only
Cisco IOS XE SD-WAN 16.10.3 When Installed On Integrated Services Virtual: version router only
Cisco IOS XE SD-WAN 16.10.3a When Installed On 1000 Series Integrated Services: version routers only
Cisco IOS XE SD-WAN 16.10.3a When Installed On 4000 Series Integrated Services: version routers only
Cisco IOS XE SD-WAN 16.10.3a When Installed On Asr 1000 Series Aggregation Services: version routers only
Cisco IOS XE SD-WAN 16.10.3a When Installed On Cloud Services Router 1000v: version series only
Cisco IOS XE SD-WAN 16.10.3a When Installed On Integrated Services Virtual: version router only
Cisco IOS XE SD-WAN 16.10.3b When Installed On 1000 Series Integrated Services: version routers only
Cisco IOS XE SD-WAN 16.10.3b When Installed On 4000 Series Integrated Services: version routers only
Cisco IOS XE SD-WAN 16.10.3b When Installed On Asr 1000 Series Aggregation Services: version routers only
Cisco IOS XE SD-WAN 16.10.3b When Installed On Cloud Services Router 1000v: version series only
Cisco IOS XE SD-WAN 16.10.3b When Installed On Integrated Services Virtual: version router only
Cisco IOS XE SD-WAN 16.10.4 When Installed On 1000 Series Integrated Services: version routers only
and 121 more

Published 2021-09-23. Last modified 2026-06-17.