CVE-2020-3284

Cisco IOS XR Software Enhanced Preboot eXecution Environment Unsigned Code Execution Vulnerability

Published Nov 6, 2020 CVSS 3.1 · 9.8 Critical EPSS 2.9% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2020-24555 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.
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Subscriptions

Cisco A99-rp2-se A99-rp2-se Firmware A99-rp2-tr A99-rp2-tr Firmware A99-rp3-se A99-rp3-se Firmware A99-rp3-tr A99-rp3-tr Firmware A99-rsp-se A99-rsp-se Firmware A99-rsp-tr A99-rsp-tr Firmware A9k-rsp5-se A9k-rsp5-se Firmware A9k-rsp5-tr A9k-rsp5-tr Firmware A9k-rsp880-lt-se A9k-rsp880-lt-se Firmware A9k-rsp880-lt-tr A9k-rsp880-lt-tr Firmware A9k-rsp880-se A9k-rsp880-se Firmware A9k-rsp880-tr A9k-rsp880-tr Firmware Asr-9901-rp Asr-9901-rp Firmware Ios Xr N540-12z20g-sys-a\/d N540-12z20g-sys-a\/d Firmware N540-24z8q2c-m N540-24z8q2c-m Firmware N540-28z4c-sys-a\/d N540-28z4c-sys-a\/d Firmware N540-acc-sys N540-acc-sys Firmware N540x-12z16g-sys-a\/d N540x-12z16g-sys-a\/d Firmware N540x-16z4g8q2c-a\/d N540x-16z4g8q2c-a\/d Firmware N560-4-sys N560-4-sys Firmware N560-7-sys N560-7-sys Firmware Nc55-rp Nc55-rp-e Nc55-rp-e Firmware Nc55-rp Firmware Ncs-5501 Ncs-5501-se Ncs-5501-se Firmware Ncs-5501 Firmware Ncs-5502 Ncs-5502-se Ncs-5502-se Firmware Ncs-5502 Firmware Ncs-55a1-24h Ncs-55a1-24h Firmware Ncs-55a1-24q6h-s Ncs-55a1-24q6h-s Firmware Ncs-55a1-36h-s Ncs-55a1-36h-s Firmware Ncs-55a1-36h-se-s Ncs-55a1-36h-se-s Firmware Ncs-55a2-mod-hd-s Ncs-55a2-mod-hd-s Firmware Ncs-55a2-mod-hx-s Ncs-55a2-mod-hx-s Firmware Ncs-55a2-mod-s Ncs-55a2-mod-s Firmware Ncs-55a2-mod-se-h-s Ncs-55a2-mod-se-h-s Firmware Ncs-55a2-mod-se-s Ncs-55a2-mod-se-s Firmware Ncs1001 Ncs1001 Firmware Ncs1002 Ncs1002 Firmware Ncs1004 Ncs1004 Firmware Ncs5001 Ncs5001 Firmware Ncs5002 Ncs5002 Firmware Ncs5011 Ncs5011 Firmware Ncs55-a1-48q6h Ncs55-a1-48q6h Firmware
Weaknesses

Sources

Status
PUBLISHED
Assigner
cisco
Published
Updated
Nov 13, 2024, 5:43 PM
Reserved
Dec 12, 2019, 12:00 AM
Status
Modified
Published
Nov 6, 2020, 7:15 PM
Modified
Jun 17, 2026, 3:17 AM