CVE-2021-34770

Cisco IOS XE Software for Catalyst 9000 Family Wireless Controllers CAPWAP Remote Code Execution Vulnerability

CRITICAL
9.8
CVSS Score
Published: September 23, 2021 at 02:27 AM UTC
Updated: June 17, 2026 at 03:56 AM UTC
11 products affected across 1 vendorIOS XeCatalyst 9800-LCatalyst 9800-80

Using Cisco IOS XE Software by Cisco?

Get instant alerts when new vulnerabilities affect Cisco IOS XE Software - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
CRITICAL9.8
Exploit prediction
EPSS 3%
SSVC
No known exploit

Description

A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, remote attacker to execute arbitrary code with administrative privileges or cause a denial of service (DoS) condition on an affected device. The vulnerability is due to a logic error that occurs during the validation of CAPWAP packets. An attacker could exploit this vulnerability by sending a crafted CAPWAP packet to an affected device. A successful exploit could allow the attacker to execute arbitrary code with administrative privileges or cause the affected device to crash and reload, resulting in a DoS condition.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

cisco-catalyst-9800 (environment) · cisco-catalyst-9800-40 (environment) · cisco-catalyst-9800-40-wireless-controller (environment) · cisco-catalyst-9800-80 (environment) · cisco-catalyst-9800-80-wireless-controller (environment) · cisco-catalyst-9800-cl (environment) · cisco-catalyst-9800-embedded-wireless-controller (environment) · cisco-catalyst-9800-l (environment) · cisco-catalyst-9800-l-c (environment) · cisco-catalyst-9800-l-f (environment)
All versions
All versions
All versions
All versions
All versions
All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-122CWE-787

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card