CVE-2025-8870 PUBLISHED

On affected platforms running Arista EOS, certain serial console input might result in an unexpected reload of the device.

Assigner: Arista
Reserved: 11.08.2025 Published: 14.11.2025 Updated: 14.11.2025

On affected platforms running Arista EOS, certain serial console input might result in an unexpected reload of the device.153

CVSS Vector: CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H
CVSS Score: 4.9

Attack Vector	Physical	Scope	Changed
Attack Complexity	High	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	High

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:P/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
CVSS Score: 5.6

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Physical	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	Present	Availability	High	Availability	High
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	Arista Networks
Product	EOS
Versions	Default: unaffected Version 4.34.2FX is affected

Affected Configurations

In order to be vulnerable to CVE-2025-8870, both of the following conditions must be met:

An attacker must have a serial interface connection to the device or access to remotely access the console via the console port. Network remote access does not cause this issue.

AND

Device must be using the Synopsys Designware serial model:

<h1>bash dmesg | grep "Synopsys DesignWare"</h1>

[ 1.287358] 10200000.serial: ttyS0 at MMIO 0x10200000 (irq = 15, base_baud = 15625000) is a Synopsys DesignWare

[ 1.287845] 10201000.serial: ttyS1 at MMIO 0x10201000 (irq = 164, base_baud = 15625000) is a Synopsys DesignWare

Workarounds

The mitigation is to limit access to the serial console.

Solutions

The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Arista recommends customers move to the latest version of each release that contains all the fixes listed below. For more information about upgrading see EOS User Manual: Upgrades and Downgrades https://www.arista.com/en/um-eos/eos-upgrades-and-downgrades

CVE-2025-8870 has been fixed in the following releases:

4.35.0F and later releases

References

https://www.arista.com/en/support/advisories-notices/security-advisory/22811-security-advisory-0125

Problem Types

CWE-248 CWE

Impacts

CAPEC-153 Input Data Manipulation