Cisco IOS XR up to 7.11.1 System-to-Intermediate System Protocol denial of service

Summaryinfo

A vulnerability marked as critical has been reported in Cisco IOS XR. This vulnerability affects unknown code of the component System-to-Intermediate System Protocol Handler. This manipulation causes denial of service. This vulnerability is registered as CVE-2024-20406. The attack requires access to the local network. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Cisco IOS XR. It has been declared as critical. Affected by this vulnerability is an unknown code of the component System-to-Intermediate System Protocol Handler. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. The summary by CVE is:

A vulnerability in the segment routing feature for the Intermediate System-to-Intermediate System (IS-IS) protocol of Cisco IOS XR 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 of ingress IS-IS packets. An attacker could exploit this vulnerability by sending specific IS-IS packets to an affected device after forming an adjacency. A successful exploit could allow the attacker to cause the IS-IS process on all affected devices that are participating in the Flexible Algorithm to crash and restart, resulting in a 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 must have formed an adjacency. This vulnerability affects segment routing for IS-IS over IPv4 and IPv6 control planes as well as devices that are configured as level 1, level 2, or multi-level routing IS-IS type.

The advisory is shared at sec.cloudapps.cisco.com. This vulnerability is known as CVE-2024-20406 since 11/08/2023. The exploitation appears to be easy. The attack needs to be initiated within the local network. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available.

Upgrading eliminates this vulnerability.

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Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• IOS XR

Version

• 6.8.1
• 6.8.2
• 6.9.1
• 6.9.2
• 7.4.1
• 7.4.2
• 7.4.15
• 7.4.16
• 7.5.1
• 7.5.2
• 7.5.3
• 7.5.4
• 7.5.5
• 7.5.12
• 7.6.1
• 7.6.2
• 7.6.3
• 7.6.15
• 7.7.1
• 7.7.2
• 7.7.21
• 7.8.1
• 7.8.2
• 7.8.22
• 7.9.1
• 7.9.2
• 7.9.21
• 7.10.1
• 7.10.2
• 7.11.1

License

• commercial

Website

• Vendor: https://www.cisco.com/

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