CVE-2025-20189

highpriority · track · 0EPSS 0.002 · 16 %ileDEEUNLRUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.25% (16th) EPSS
CVSS 7.4 · high
Is it mine?
891 products
Check your exposure
Who says so?
6 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

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.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

7.4
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.8–7.4

v3.17.4highAV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU
v3.17.4highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · ENISA EU
v3.17.4highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · psirt@cisco.com USexploitability 2.8 · impact 4
v3.16.8mediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
v3.17.4highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · NCSC-NL NL
v3.17.4highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · Cisco PSIRT US
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

05

affected products (891)

Products and version ranges known to be affected.

06

advisories (3)

Vendor and ecosystem advisories describing this.

  • NCSC-2025-0146Kwetsbaarheden verholpen in Cisco IOS XE SoftwareNL2025-05-08csaf · ncsc_nlNL

    Cisco heeft kwetsbaarheden verholpen in Cisco IOS XE Software.

  • WID-SEC-W-2025-0973Cisco IOS XE Software for Cisco ASR 903 Aggregation Services Routers: Schwachstelle ermöglicht Denial of ServiceDeutsch2025-05-07csaf · cert_bundDE

    Ein Angreifer aus einem angrenzenden Netzwerk kann eine Schwachstelle in Cisco IOS XE Software for Cisco ASR 903 Aggregation Services Routers ausnutzen, um einen Denial of Service Angriff durchzuführen.

  • cisco-sa-asr903-rsp3-arp-dos-WmfzdvJZCisco IOS XE Software for Cisco ASR 903 Aggregation Services Routers ARP Denial of Service Vulnerability2025-05-07csaf · cisco_csafUS

    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. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is part of the May 2025 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: May 2025 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75279"].

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

09

references (4)

External citations — patches, advisories, analysis.

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