#VU115157 Resource exhaustion in Cisco IOS XR - CVE-2025-20340

Vulnerability identifier: #VU115157

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-20340

CWE-ID: CWE-400

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
Cisco IOS XR
Operating systems & Components / Operating system

Vendor: Cisco Systems, Inc

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to application does not properly control consumption of internal resources in the Address Resolution Protocol (ARP) implementation. A remote attacker on the local network can trigger resource exhaustion and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco IOS XR: -, 7.11, 24.1, 24.2, 24.3, 24.4, 25.1, 25.2

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External links
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-arp-storm-EjUU55yM

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.