What is the CVSS score of CVE-2020-3284?

CVE-2020-3284 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 2.8%.

A9K Rsp880 Se Firmware CVE-2020-3284

CRITICAL

Improper Access Control (CWE-284)

2020-11-06 psirt@cisco.com

Cisco Authentication Bypass Apple A9K Rsp880 Se Firmware Ios Xr A9K Rsp880 Tr Firmware A99 Rp2 Se Firmware A99 Rp2 Tr Firmware A99 Rsp Se Firmware A99 Rsp Tr Firmware A9K Rsp880 Lt Se Firmware A9K Rsp880 Lt Tr Firmware Asr 9901 Rp Firmware A99 Rp3 Se Firmware A99 Rp3 Tr Firmware A9K Rsp5 Se Firmware A9K Rsp5 Tr Firmware Ncs1001 Firmware Ncs1002 Firmware Ncs1004 Firmware N540 12Z20G Sys A D Firmware N540 24Z8Q2C M Firmware N540 28Z4C Sys A D Firmware N540 Acc Sys Firmware N540X 16Z4G8Q2C A D Firmware N540X 12Z16G Sys A D Firmware N560 4 Sys Firmware N560 7 Sys Firmware Ncs5001 Firmware Ncs5002 Firmware Ncs5011 Firmware Nc55 Rp Firmware Nc55 Rp E Firmware Ncs 5501 Firmware Ncs 5501 Se Firmware Ncs 5502 Firmware Ncs 5502 Se Firmware Ncs 55A2 Mod S Firmware Ncs 55A2 Mod Hd S Firmware Ncs 55A2 Mod Hx S Firmware Ncs 55A2 Mod Se S Firmware Ncs 55A2 Mod Se H S Firmware Ncs 55A1 36H Se S Firmware Ncs 55A1 36H S Firmware Ncs 55A1 24H Firmware Ncs55 A1 48Q6H Firmware Ncs 55A1 24Q6H S Firmware

9.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Nov 06, 2020 - 19:15 nvd

CRITICAL 9.8

DescriptionNVD

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.

AnalysisAI

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. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Technical ContextAI

This vulnerability is classified under CWE-284. 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. Affected products include: Cisco A9K-Rsp880-Se Firmware, Cisco Ios Xr, Cisco A9K-Rsp880-Tr Firmware, Cisco A99-Rp2-Se Firmware, Cisco A99-Rp2-Tr Firmware.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.