CVE-2024-20312

State: Published
Severity: 7.4 High
Published: Mar 27, 2024
Updated: Aug 26, 2025
Reserved: Nov 8, 2023

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.

Scores

CVSS	Score	Vector	Source
3.1	7.4 High	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H	cisco

Weaknesses

CWE-476 NULL Pointer Dereference

Affected Products

Product	Versions
IOSCisco	15.2(1)SAffected 15.2(2)SAffected 15.2(1)S1Affected 15.2(4)SAffected 15.2(1)S2Affected 15.2(2)S1Affected 15.2(2)S2Affected 15.2(2)S0aAffected 15.2(2)S0cAffected 15.2(4)S1Affected 15.2(4)S4Affected 15.2(4)S6Affected 15.2(4)S2Affected 15.2(4)S5Affected 15.2(4)S3Affected 15.2(4)S3aAffected 15.2(4)S4aAffected 15.2(4)S7Affected 15.3(1)TAffected 15.3(2)TAffected 15.3(1)T1Affected 15.3(1)T2Affected 15.3(1)T3Affected 15.3(1)T4Affected 15.3(2)T1Affected and 401 more versions
Cisco IOS XE SoftwareCisco	3.7.0SAffected 3.7.1SAffected 3.7.2SAffected 3.7.3SAffected 3.7.4SAffected 3.7.5SAffected 3.7.6SAffected 3.7.7SAffected 3.7.4aSAffected 3.7.2tSAffected 3.7.0bSAffected 3.7.1aSAffected 3.8.0SAffected 3.8.1SAffected 3.8.2SAffected 3.9.1SAffected 3.9.0SAffected 3.9.2SAffected 3.9.1aSAffected 3.9.0aSAffected 3.2.0SEAffected 3.2.1SEAffected 3.2.2SEAffected 3.2.3SEAffected 3.3.0SEAffected and 360 more versions

Product

Versions

IOSCisco

15.2(1)SAffected
15.2(2)SAffected
15.2(1)S1Affected
15.2(4)SAffected
15.2(1)S2Affected
15.2(2)S1Affected
15.2(2)S2Affected
15.2(2)S0aAffected
15.2(2)S0cAffected
15.2(4)S1Affected
15.2(4)S4Affected
15.2(4)S6Affected
15.2(4)S2Affected
15.2(4)S5Affected
15.2(4)S3Affected
15.2(4)S3aAffected
15.2(4)S4aAffected
15.2(4)S7Affected
15.3(1)TAffected
15.3(2)TAffected
15.3(1)T1Affected
15.3(1)T2Affected
15.3(1)T3Affected
15.3(1)T4Affected
15.3(2)T1Affected
and 401 more versions

Cisco IOS XE SoftwareCisco

3.7.0SAffected
3.7.1SAffected
3.7.2SAffected
3.7.3SAffected
3.7.4SAffected
3.7.5SAffected
3.7.6SAffected
3.7.7SAffected
3.7.4aSAffected
3.7.2tSAffected
3.7.0bSAffected
3.7.1aSAffected
3.8.0SAffected
3.8.1SAffected
3.8.2SAffected
3.9.1SAffected
3.9.0SAffected
3.9.2SAffected
3.9.1aSAffected
3.9.0aSAffected
3.2.0SEAffected
3.2.1SEAffected
3.2.2SEAffected
3.2.3SEAffected
3.3.0SEAffected
and 360 more versions

References

cisco-sa-isis-sGjyOUHX

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.