Arista EOS CVE-2025-6188 Authentication Bypass via UDP Port 3503

Key Information Vulnerability Overview CVE ID: CVE-2025-6188 CVSS v3.1 Base Score: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N) Common Weakness Enumeration: CWE-288 Authentication Bypass Using Alternate Path or Channel Tracking Number: BUG 1008673 Description When running Arista EOS on affected platforms, maliciously crafted UDP packets (source port 3503) may be accepted by EOS. UDP port 3503 is associated with Isping Echo Reply. This could lead to unintended behavior, particularly for UDP-based services that do not perform any form of authentication. Affected Software EOS Versions: - 4.33.1F and earlier (4.33.X line) - 4.33.1.2F and earlier (4.33.1.X line) - 4.32.4.1M and earlier (4.32.X line) - 4.31.9M and earlier (4.31.X line) - 4.30.1.1M and earlier (4.30.X line) Affected Platforms Arista EOS-based Products: - 710 Series - 720D Series - 720XP/722XP Series - 750X Series 一 7010 Series - 7010A Series - 7020P Series - 7130 Series running EOS - 7150 Series - 7190 Series - 7190z Series - 7050X/72Z/X5/X6 Series - 7000X/72X/74X/76X/79X Series - 7250X Series - 7200X/X5 Series - 7250R/R6/R7/R3 Series - 7300X Series - 7302X Series - 7358X Series - 7308X4 Series - 7358X5 Series - 7000S/7304X Series - 7000R/7304X Series - AFW 8000 Series - AWT 7200N Series - CloudEOS - cEOS-lab - vEOS-lab Required Configuration for Exploitation EOS devices are vulnerable to CVE-2025-6188 by default; no specific configuration is required. Indicators of Compromise There are no reliable means to determine if a compromise has occurred. Mitigation For EOS versions 4.28.1 and above, if MPLS is not used on the EOS device, a custom control plane ACL can be applied to remove rules allowing traffic from source port 3503. For EOS versions 4.22.0 and above, the “mpls ping” service ACL can be applied to restrict traffic on source/destination port 3503. Solution It is recommended to upgrade to the latest software version, which includes all fixes listed in each release.

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Arista EOS CVE-2025-6188 Authentication Bypass via UDP Port 3503