7.4

CVE-2020-3511: cisco cisco_ios Improper Input Validation

CVSS: 7.4v3.0HighModified
Published 24-09-2020Last modified 13-11-2024
Open JSON

Vulnerability summary

CVE-2020-3511 is a high (CVSS 7.4) Improper Input Validation vulnerability in cisco cisco_ios. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.1% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.4/10
010
High · v3.0 (CVE.org)
EPSS score
0.43%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 24-09-2020
    PublishedVulnerability first disclosed.
  2. 13-11-2024
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 2 sources · 3 versions

EPSS trend

Probability

0.43%

Chance of exploitation in the next 30 days

Percentile

36%

Versus all other CVEs

30-day change

0.00 pp

From 0.43% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.43%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cisco2 products

1 vendor · 2 products

References

1 links