What’s Vulnerable › Vulnerabilities

CVE-2020-3359: Cisco IOS XE Software for Catalyst 9800 Series Wireless Controllers Multicast DNS Denial of Service Vulnerability

• Severity: high (CVSS 8.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-09-24 · updated 2026-06-17
• Weakness: CWE-20

Description

A vulnerability in the multicast DNS (mDNS) feature of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to improper validation of mDNS packets. An attacker could exploit this vulnerability by sending a crafted mDNS packet to an affected device. A successful exploit could cause a device to reload, resulting in a DoS condition.

Affected products

• Cisco IOS XE: 16.12.1

References

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-mdns-dos-3tH6cA9J
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-mdns-dos-3tH6cA9J

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