CVE-2021-1453

CVE-2021-1453 is a medium-severity vulnerability in Cisco Ios Xe with a CVSS 3.x base score of 6.8. 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-347.

Key facts

Description

A vulnerability in the software image verification functionality of Cisco IOS XE Software for the Cisco Catalyst 9000 Family of switches could allow an unauthenticated, physical attacker to execute unsigned code at system boot time. The vulnerability is due to an improper check in the code function that manages the verification of the digital signatures of system image files during the initial boot process. An attacker could exploit this vulnerability by loading unsigned software on an affected device. A successful exploit could allow the attacker to boot a malicious software image or execute unsigned code and bypass the image verification check part of the secure boot process of an affected device. To exploit this vulnerability, the attacker would need to have unauthenticated physical access to the device or obtain privileged access to the root shell on the device.

Frequently asked questions

What is CVE-2021-1453?
A vulnerability in the software image verification functionality of Cisco IOS XE Software for the Cisco Catalyst 9000 Family of switches could allow an unauthenticated, physical attacker to execute unsigned code at system boot time. The vulnerability is due to an improper check in the code function that manages the verification of the digital signatures of system image files during the initial boot process. An attacker could exploit this vulnerability by loading unsigned software on an affected device. A successful exploit could allow the attacker to boot a malicious software image or execute unsigned code and bypass the image verification check part of the secure boot process of an affected device. To exploit this vulnerability, the attacker would need to have unauthenticated physical access to the device or obtain privileged access to the root shell on the device.
How severe is CVE-2021-1453?
CVE-2021-1453 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-1453 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1453?
CVE-2021-1453 primarily affects Cisco Ios Xe. In total, 55 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1453?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-1453 published?
CVE-2021-1453 was published on 2021-03-24 and last updated on 2026-06-17.

References

Affected products (55)

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