CVE-2025-20189
HIGHDescription
A vulnerability in the Cisco Express Forwarding functionality of Cisco IOS XE Software for Cisco ASR 903 Aggregation Services Routers with Route Switch Processor 3 (RSP3C) could allow an unauthenticated, adjacent attacker to trigger a denial of service (DoS) condition. This vulnerability is due to improper memory management when Cisco IOS XE Software is processing Address Resolution Protocol (ARP) messages. An attacker could exploit this vulnerability by sending crafted ARP messages at a high rate over a period of time to an affected device. A successful exploit could allow the attacker to exhaust system resources, which eventually triggers a reload of the active route switch processor (RSP). If a redundant RSP is not present, the router reloads.
How to fix
No published remediation has been found for this vulnerability's affected products yet.
Mitigation guidance may be in the linked vendor advisories in the References section below.
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CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Exploit Intelligence
Low risk: more likely to be exploited than 15% of all known CVEs.
References
Related Vulnerabilities
Other CWE-762 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2023-41056 | High | 8.1 | 2.6% | - | Fix |
| CVE-2024-2955 | High | 7.8 | 1.4% | - | Fix |
| CVE-2025-48431 | High | 7.5 | 1.1% | - | Fix |
| CVE-2023-45510 | High | 7.5 | 0.6% | - | - |
| CVE-2025-47737 | Low | 2.9 | 0.5% | - | - |
| CVE-2024-4853 | Low | 3.6 | 0.4% | - | Fix |
Common questions
How do I fix CVE-2025-20189?
No published fix for CVE-2025-20189 has been found yet. Check the linked vendor advisories for guidance as it becomes available.
Is CVE-2025-20189 being actively exploited?
Not that we know of. CVE-2025-20189 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.24% is the estimated probability that it will be exploited in the next 30 days. That is higher than 15% of all scored CVEs.
How severe is CVE-2025-20189?
CVE-2025-20189 has a CVSS v3 base score of 7.4, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-08-05.