cisco-sa-xrsig-UY4zRUCG

Cisco IOS XR Software Image Verification Bypass Vulnerability

A vulnerability in the installation process of Cisco IOS XR Software could allow an authenticated, local attacker to bypass Cisco IOS XR Software image signature verification and load unsigned 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 during the installation of an .iso file. An attacker could exploit this vulnerability by modifying contents of the .iso image and then installing and activating it on the device. A successful exploit could allow the attacker to load an unsigned file as part of the image activation process. 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. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is part of the September 2025 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2025 Semiannual Cisco IOS XR Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75549"].