CVE-2024-20436: Cisco IOS XE

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

A vulnerability in the HTTP Server feature of Cisco IOS XE Software when the Telephony Service feature is enabled could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to a null pointer dereference when accessing specific URLs. An attacker could exploit this vulnerability by sending crafted HTTP traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, causing a DoS condition on the affected device.

Affected products

• Cisco IOS XE: version 3.9.0as only; version 3.9.1s only; version 3.9.2s only; version 3.10.0s only; version 3.10.1s only; version 3.10.2s only; …

Published 2024-09-25. Last modified 2026-06-17.