CVE-2025-20160

Severity CVSS v4.0:

Pending analysis

Type:

CWE-287 Authentication Issues

Publication date:

24/09/2025

Last modified:

26/09/2025

Description

A vulnerability in the implementation of the TACACS+ protocol in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to view sensitive data or bypass authentication. <br /> <br /> This vulnerability exists because the system does not properly check whether the required TACACS+ shared secret is configured. A machine-in-the-middle attacker could exploit this vulnerability by intercepting and reading unencrypted TACACS+ messages or impersonating the TACACS+ server and falsely accepting arbitrary authentication requests. A successful exploit could allow the attacker to view sensitive information in a TACACS+ message or bypass authentication and gain access to the affected device.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 8.10 HIGH
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

8.10

Severity 3.x

HIGH

References to Advisories, Solutions, and Tools

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-tacacs-hdB7thJw