CVE-2021-1423 | Cisco Aironet Access Points Arbitrary File Overwrite Vulnerability

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.

Published: 2021-03-24 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-1423 is rated Low Risk (22.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.23%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-1423

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.06% 0.23% +0.17%
2 2025-03-17 0.04% 0.06% +0.02%
3 2023-03-07 — 0.04% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-1423

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.4 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 0.8 3.6 [email protected]
4.4 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 0.8 3.6 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 3.9 2.9 [email protected]

Weakness enumeration for CVE-2021-1423

Affected software / configurations for CVE-2021-1423

Vendor Product Version Raw CPE
cisco aironet_access_point_software — cpe:2.3:a:cisco:aironet_access_point_software:-:*:*:*:*:*:*:*
cisco catalyst_9800_firmware < 16.12.5 cpe:2.3:o:cisco:catalyst_9800_firmware:*:*:*:*:*:*:*:*
cisco catalyst_9800_firmware >= 17.1, <= 17.2 cpe:2.3:o:cisco:catalyst_9800_firmware:*:*:*:*:*:*:*:*
cisco wireless_lan_controller_software < 8.5.171.0 cpe:2.3:a:cisco:wireless_lan_controller_software:*:*:*:*:*:*:*:*
cisco wireless_lan_controller_software >= 8.6, < 8.10.130.0 cpe:2.3:a:cisco:wireless_lan_controller_software:*:*:*:*:*:*:*:*

References for CVE-2021-1423

cvelogic Threat Intelligence