AUGUST 4, 2026
Live Feed
Back to database
Case File

CVE-2020-3511

HIGH · CVSS 7.4 EPSS 0.43% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2020-09-24 · Last synced 2026-08-04

CyberRota Analysis

This is a high severity vulnerability with a CVSS score of 7.4. It affects Cisco. Public exploit code or proof-of-concept references have been detected in its references. It may lead to a denial-of-service condition.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
exploit

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2020-3511
Severity
HIGH
CVSS
7.4
EPSS
0.43%
Cisco

Original NVD 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.

Related CVEs

Other vulnerabilities affecting the same vendor(s)