CVE-2025-20177: Cisco IOS XR Software Image Verification Bypass Vulnerability

Severity: medium (CVSS 6.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-03-12 · updated 2026-06-17
Weakness: CWE-274

Description

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.

Affected products

Cisco IOS XR Software: before 7.11.21; from 24.2 before 24.2.2; from 24.3 before 24.3.2; 24.4 — fixed in 24.2.2, 24.3.2, 7.11.21

How to fix

Upgrade to a fixed version: Cisco IOS XR Software 24.2.2, 24.3.2, 7.11.21. Check the vendor advisory for mitigations.

References

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