How severe is CVE-2020-3284?

CVE-2020-3284 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-3284 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3284?

CVE-2020-3284 primarily affects Cisco A9k-rsp880-se Firmware. In total, 44 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-3284?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2020-3284 published?

CVE-2020-3284 was published on 2020-11-06 and last updated on 2026-06-17.

CVE-2020-3284

CVE-2020-3284 is a critical-severity vulnerability in Cisco A9k-rsp880-se Firmware with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-284.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 9.3
EPSS exploit prediction: 3% (85th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-284
Affected product: Cisco A9k-rsp880-se Firmware
Published: 2020-11-06
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2020-3284?: 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.
How severe is CVE-2020-3284?: CVE-2020-3284 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-3284 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3284?: CVE-2020-3284 primarily affects Cisco A9k-rsp880-se Firmware. In total, 44 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3284?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-3284 published?: CVE-2020-3284 was published on 2020-11-06 and last updated on 2026-06-17.

References

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

Affected products (44)

cpe:2.3:o:cisco:a9k-rsp880-se_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:a9k-rsp880-tr_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:a99-rp2-se_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:a99-rp2-tr_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:a99-rsp-se_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:a99-rsp-tr_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:a9k-rsp880-lt-se_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:a9k-rsp880-lt-tr_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:asr-9901-rp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:a99-rp3-se_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:a99-rp3-tr_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:a9k-rsp5-se_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:a9k-rsp5-tr_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs1001_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs1002_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs1004_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:n540-12z20g-sys-a\/d_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:n540-24z8q2c-m_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:n540-28z4c-sys-a\/d_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:n540-acc-sys_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:n540x-16z4g8q2c-a\/d_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:n540x-12z16g-sys-a\/d_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:n560-4-sys_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:n560-7-sys_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs5001_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs5002_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs5011_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:nc55-rp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:nc55-rp-e_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs-5501_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs-5501-se_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs-5502_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs-5502-se_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs-55a2-mod-s_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs-55a2-mod-hd-s_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs-55a2-mod-hx-s_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs-55a2-mod-se-s_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs-55a2-mod-se-h-s_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ncs-55a1-36h-se-s_firmware:*:*:*:*:*:*:*:*

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