Cyber Posture

CVE-2025-27020

Critical

Published: 08 December 2025

Published
08 December 2025
Modified
22 December 2025
KEV Added
Patch
CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0019 40.2th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Description

Improper configuration of the SSH service in Infinera MTC-9 allows an unauthenticated attacker to execute arbitrary commands and access data on file system . This issue affects MTC-9: from R22.1.1.0275 before R23.0.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly prohibits critical actions like arbitrary command execution without identification or authentication, addressing the core issue of missing SSH authentication.

prevent

Requires secure configuration settings for the SSH service to enforce authentication, mitigating the improper configuration vulnerability.

prevent

Mandates timely flaw remediation via upgrades to fixed MTC-9 R23.0 or later, eliminating the SSH authentication bypass.

Security SummaryAI

CVE-2025-27020 is a vulnerability stemming from improper configuration of the SSH service in Infinera MTC-9 systems. It affects MTC-9 versions from R22.1.1.0275 up to but not including R23.0, as classified under CWE-306 (Missing Authentication for Critical Function). The issue enables unauthenticated remote access, earning a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

An unauthenticated attacker with network access can exploit this vulnerability with low complexity and no user interaction required. Successful exploitation allows execution of arbitrary commands and access to data on the file system, potentially compromising confidentiality, integrity, and availability of the affected system.

The advisory published on 2025-12-08 provides further details at https://www.cvcn.gov.it/cvcn/cve/CVE-2025-27020. Mitigation involves upgrading to MTC-9 R23.0 or later, as the vulnerability is fixed in that release.

Details

CWE(s)

Affected Products

nokia
infinera mtc-9 firmware
22.1.1.0275 — 23.0

MITRE ATT&CK Enterprise TechniquesAI

T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
Why these techniques?

The vulnerability allows unauthenticated remote access via misconfigured SSH service, enabling exploitation of remote services (T1210) which facilitates arbitrary Unix shell command execution (T1059.004).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References