CVE-2020-3284 Detail

Current Description

A vulnerability in the enhanced Preboot eXecution Environment (PXE) boot loader for Cisco IOS XR 64-bit Software could allow an unauthenticated, remote attacker to execute unsigned code during the PXE boot process on an affected device. The PXE boot loader is part of the BIOS and runs over the management interface of hardware platforms that are running Cisco IOS XR Software only. The vulnerability exists because internal commands that are issued when the PXE network boot process is loading a software image are not properly verified. An attacker could exploit this vulnerability by compromising the PXE boot server and replacing a valid software image with a malicious one. Alternatively, the attacker could impersonate the PXE boot server and send a PXE boot reply with a malicious file. A successful exploit could allow the attacker to execute unsigned code on the affected device. Note: To fix this vulnerability, both the Cisco IOS XR Software and the BIOS must be upgraded. The BIOS code is included in Cisco IOS XR Software but might require additional installation steps. For further information, see the Fixed Software section of this advisory.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  9.8 CRITICAL
Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Nist CVSS score does not match with CNA score
CNA:  Cisco Systems, Inc.
Base Score:  8.1 HIGH
Vector:  CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: It is possible that the NVD CVSS may not match that of the CNA. The most common reason for this is that publicly available information does not provide sufficient detail or that information simply was not available at the time the CVSS vector string was assigned.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-pxe-unsign-code-exec-qAa78fD2 Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
NVD-CWE-noinfo Insufficient Information cwe source acceptance level NIST  
CWE-284 Improper Access Control Contributor acceptance level Cisco Systems, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2020-3284
NVD Published Date:
11/06/2020
NVD Last Modified:
01/05/2021
Source:
Cisco Systems, Inc.