CVE-2024-20312

Name: CVE-2024-20312
Creator: NVD / NIST
Published: 2024-03-27T17:15:52.69+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.4/10EPSS 0.26%

Last modified Jun 17, 2026

CVE-2024-20312 is a high-severity vulnerability rated 7.4/10 on the CVSS scale. A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) protocol of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient input validation when parsing an ingress IS-IS packet. An attacker could exploit this vulnerability by sending a crafted IS-IS packet to an affected device after forming an adjacency. EPSS estimates a 0.26% chance of exploitation in the next 30 days.

Description

A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) protocol of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient input validation when parsing an ingress IS-IS packet. An attacker could exploit this vulnerability by sending a crafted IS-IS packet to an affected device after forming an adjacency. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. Note: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device and have formed an adjacency.

Metrics

CVSS 3.1

7.4/10

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS Probability

0.26%

16.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-476

Affected Software

Vendor	Product	Versions
Cisco	Ios	15.0\(1\)ex
Cisco	Ios	15.1\(1\)sy
Cisco	Ios	15.1\(1\)sy1
Cisco	Ios	15.1\(1\)sy2
Cisco	Ios	15.1\(1\)sy3
Cisco	Ios	15.1\(1\)sy4
Cisco	Ios	15.1\(1\)sy5
Cisco	Ios	15.1\(1\)sy6
Cisco	Ios	15.1\(2\)sg
Cisco	Ios	15.1\(2\)sg1
Cisco	Ios	15.1\(2\)sg2
Cisco	Ios	15.1\(2\)sg3
Cisco	Ios	15.1\(2\)sg4
Cisco	Ios	15.1\(2\)sg5
Cisco	Ios	15.1\(2\)sg6
Cisco	Ios	15.1\(2\)sg7
Cisco	Ios	15.1\(2\)sg8
Cisco	Ios	15.1\(2\)sy
Cisco	Ios	15.1\(2\)sy1
Cisco	Ios	15.1\(2\)sy2
Cisco	Ios	15.1\(2\)sy3
Cisco	Ios	15.1\(2\)sy4
Cisco	Ios	15.1\(2\)sy4a
Cisco	Ios	15.1\(2\)sy5
Cisco	Ios	15.1\(2\)sy6
Cisco	Ios	15.1\(2\)sy7
Cisco	Ios	15.1\(2\)sy8
Cisco	Ios	15.1\(2\)sy9
Cisco	Ios	15.1\(2\)sy10
Cisco	Ios	15.1\(2\)sy11
Cisco	Ios	15.1\(2\)sy12
Cisco	Ios	15.1\(2\)sy13
Cisco	Ios	15.1\(2\)sy14
Cisco	Ios	15.1\(2\)sy15
Cisco	Ios	15.1\(2\)sy16
Cisco	Ios	15.2\(1\)e
Cisco	Ios	15.2\(1\)e1
Cisco	Ios	15.2\(1\)e2
Cisco	Ios	15.2\(1\)e3
Cisco	Ios	15.2\(1\)ey
Cisco	Ios	15.2\(1\)s
Cisco	Ios	15.2\(1\)s1
Cisco	Ios	15.2\(1\)s2
Cisco	Ios	15.2\(1\)sy
Cisco	Ios	15.2\(1\)sy0a
Cisco	Ios	15.2\(1\)sy1
Cisco	Ios	15.2\(1\)sy1a
Cisco	Ios	15.2\(1\)sy2
Cisco	Ios	15.2\(1\)sy3
Cisco	Ios	15.2\(1\)sy4

Showing 50 of 811 affected configurations. See NVD for the full list.

References

Timeline

Published: Mar 27, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2024-20312?

How severe is CVE-2024-20312?

CVE-2024-20312 has a CVSS score of 7.4/10 (HIGH severity). The EPSS model estimates a 0.26% probability of exploitation in the next 30 days.

How do I fix CVE-2024-20312?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2024-20312?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST