SB2021020506 - Improper image signature verification in Cisco IOS XR
Published: February 5, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 secuirty vulnerabilities.
1) Improper verification of cryptographic signature (CVE-ID: CVE-2021-1136)
The vulnerability allows a local user to bypass implemented security restrictions.
The vulnerability exists in the signing functions of ISO packaging of Cisco NCS 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for the Cisco 8000 Series Routers. Unsigned script within the ISO image is not verified during system upgrade before it is executed. A local user can execute unsigned code during the boot process on an affected device.
2) Improper Verification of Cryptographic Signature (CVE-ID: CVE-2021-1244)
The vulnerability allows a local user to bypass implemented security restrictions.
Multiple vulnerabilities in Cisco Network Convergence System (NCS) 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for the Cisco 8000 Series Routers due to an unlocked version of GRUB boot loader on an affected device. Unsigned script within the ISO image is not verified during system upgrade before it is executed. A local user can modifying the boot process from the GRUB menu and bypass the boot chain of trust.
Remediation
Install update from vendor's website.