How severe is CVE-2021-1423?

CVE-2021-1423 has a CVSS 3.x base score of 4.4, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2021-1423 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-1423?

CVE-2021-1423 primarily affects Cisco Aironet Access Point Software. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-1423?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-1423 published?

CVE-2021-1423 was published on 2021-03-24 and last updated on 2026-06-17.

CVE-2021-1423

CVE-2021-1423 is a medium-severity vulnerability in Cisco Aironet Access Point Software with a CVSS 3.x base score of 4.4. 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-668.

Key facts

Severity: Medium (CVSS 3.x base score 4.4)
CVSS v2: 2.1
EPSS exploit prediction: 0% (14th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-668
Affected product: Cisco Aironet Access Point Software
Published: 2021-03-24
Last modified: 2026-06-17

Description

A vulnerability in the implementation of a CLI command in Cisco Aironet Access Points (AP) could allow an authenticated, local attacker to overwrite files in the flash memory of the device. This vulnerability is due to insufficient input validation for a specific command. An attacker could exploit this vulnerability by issuing a command with crafted arguments. A successful exploit could allow the attacker to overwrite or create files with data that is already present in other files that are hosted on the affected device.

Frequently asked questions

What is CVE-2021-1423?: A vulnerability in the implementation of a CLI command in Cisco Aironet Access Points (AP) could allow an authenticated, local attacker to overwrite files in the flash memory of the device. This vulnerability is due to insufficient input validation for a specific command. An attacker could exploit this vulnerability by issuing a command with crafted arguments. A successful exploit could allow the attacker to overwrite or create files with data that is already present in other files that are hosted on the affected device.
How severe is CVE-2021-1423?: CVE-2021-1423 has a CVSS 3.x base score of 4.4, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2021-1423 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1423?: CVE-2021-1423 primarily affects Cisco Aironet Access Point Software. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1423?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-1423 published?: CVE-2021-1423 was published on 2021-03-24 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ap-foverwrt-HyVXvrtb

Affected products (3)

cpe:2.3:a:cisco:aironet_access_point_software:-:*:*:*:*:*:*:*
cpe:2.3:o:cisco:catalyst_9800_firmware:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:wireless_lan_controller_software:*:*:*:*:*:*:*:*

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