VULNERABILITY INTELLIGENCE

CVE-2020-3511

CVSS score7.4 HIGH
EPSS probability0.43%
CISA KEVNot currently listed
Published2020-09-24
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Description

A vulnerability in the ISDN subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient input validation when the ISDN Q.931 messages are processed. An attacker could exploit this vulnerability by sending a malicious ISDN Q.931 message to an affected device. A successful exploit could allow the attacker to cause the process to crash, resulting in a reload of the affected device.

Weakness classification

  • psirt@cisco.com: CWE-20
  • nvd@nist.gov: CWE-20

Primary references