Cisco NX-OS Bootloader access control

Summaryinfo

A vulnerability was found in Cisco NX-OS, NX-OS System Software in ACI Mode, Unified Computing System and Unified Computing System Managed. It has been rated as critical. This issue affects some unknown processing of the component Bootloader. The manipulation leads to access control. This vulnerability is referenced as CVE-2024-20397. It is possible to launch the attack on the physical device. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Cisco NX-OS, NX-OS System Software in ACI Mode, Unified Computing System and Unified Computing System Managed (version unknown). This issue affects an unknown function of the component Bootloader. The manipulation with an unknown input leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

A vulnerability in the bootloader of Cisco NX-OS Software could allow an unauthenticated attacker with physical access to an affected device, or an authenticated, local attacker with administrative credentials, to bypass NX-OS image signature verification. This vulnerability is due to insecure bootloader settings. An attacker could exploit this vulnerability by executing a series of bootloader commands. A successful exploit could allow the attacker to bypass NX-OS image signature verification and load unverified software.

It is possible to read the advisory at sec.cloudapps.cisco.com. The identification of this vulnerability is CVE-2024-20397 since 11/08/2023. The exploitation is known to be easy. Attacking locally is a requirement. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 12/18/2024). The attack technique deployed by this issue is T1068 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 213166 (Cisco NX-OS Software Image Verification Bypass (cisco-sa-nxos-image-sig-bypas-pQDRQvjL)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (213166). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Virtualization Software

Vendor

• Cisco

Name

• NX-OS
• NX-OS System Software in ACI Mode
• Unified Computing System
• Unified Computing System Managed

License

• commercial

Website

• Vendor: https://www.cisco.com/

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Be aware that VulDB is the high quality source for vulnerability data.

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