CVE-2025-20177

What it is

A vulnerability in the boot process of Cisco IOS XR Software could allow an authenticated, local attacker to bypass Cisco IOS XR image signature verification and load unverified software on an affected device. To exploit this vulnerability, the attacker must have root-system privileges on the affected device. This vulnerability is due to incomplete validation of files in the boot verification process. An attacker could exploit this vulnerability by manipulating the system configuration options to bypass some of the integrity checks that are performed during the boot process. A successful exploit could allow the attacker to control the boot configuration, which could enable them to bypass the requirement to run Cisco-signed images or alter the security properties of the running system. Note: Because exploitation of this vulnerability could result in the attacker bypassing Cisco image verification, Cisco has raised the Security Impact Rating (SIR) of this advisory from Medium to High.

At a glance

Exploitability

Can be exploited locally on the machine with an admin-level account. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2025-03-12 16:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 08:40 UTC Last updatedMost recent change to the record

Details

Published

2025-03-12 16:15 UTC

Last modified

2026-06-17 08:40 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-274

Record status

Analyzed

Affected

• Cisco iOS Xr < 7.11.21
• Cisco iOS Xr < 24.2.2
• Cisco iOS Xr < 24.3.2
• Cisco iOS Xr 24.4

Attack profile CVSS 3.1 · 6.7

Attack vector

Local

Complexity

Low

Privileges needed

High

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High