Software image verification bypass in Cisco NX-OS

1) Improper Verification of Cryptographic Signature

EUVDB-ID: #VU101221

Risk: Low

CVSSv4.0: 4 [CVSS:4.0/AV:P/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2024-20397

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

Exploit availability: No

Description

The vulnerability allows a local user to bypass implemented security restrictions.

The vulnerability exists due to improper signature verification in the bootloader. An attacker with physical access to device or a user with administrative privileges can bypass NX-OS image signature verification and load unverified software.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Cisco NX-OS: before 8.4(10)

Cisco UCS: before 4.1(3n)

CPE2.3

• cpe:2.3:o:cisco_systems:cisco_nx-os:*:*:*:*:*:*:*:*
• cpe:2.3:a:cisco_systems:cisco_ucs:*:*:*:*:*:*:*:*

External links

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-image-sig-bypas-pQDRQvjL
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwh76163
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwh76166
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwj35846
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwm47438
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwn11901

Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.