CyberSecBulletin
CVE-2025-6188NVD status: Deferred

EOS: Authentication Bypass by Spoofing

Published Updated By the CyberSecBulletin desk

CVE-2025-6188 is a high-severity authentication bypass by spoofing vulnerability in EOS from Arista Networks, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected EOS versions: 4.33.0 through 4.33.1F; 4.33.1.0 through 4.33.1.2F; 4.32.4.0 through 4.32.4.1M, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.42% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of EOS you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on arista.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Arista NetworksEOS4.33.0 through 4.33.1F; 4.33.1.0 through 4.33.1.2F; 4.32.4.0 through 4.32.4.1M; 4.31.0 through 4.31.6M; 4.30.0 through 4.30.9.1MNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by CNA (arista.com).

Official description

On affected platforms running Arista EOS, maliciously formed UDP packets with source port 3503 may be accepted by EOS. UDP Port 3503 is associated with LspPing Echo Reply. This can result in unexpected behaviors, especially for UDP based services that do not perform some form of authentication.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Authentication Bypass by Spoofing

This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.

More Authentication Bypass by Spoofing vulnerabilities (CWE-290)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in EOS

All EOS vulnerabilities

Recent Authentication Bypass by Spoofing vulnerabilities

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