CVE-2020-3552 | Cisco Aironet Access Points Ethernet Wired Clients Denial of Service Vulnerability

A vulnerability in the Ethernet packet handling of Cisco Aironet Access Points (APs) Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by connecting as a wired client to the Ethernet interface of an affected device and sending a series of specific packets within a short time frame. A successful exploit could allow the attacker to cause a NULL pointer access that results in a reload of the affected device.

Published: 2020-09-24 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-3552 is rated Moderate Risk (43.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.48%). Mandatory action: Review affected assets and schedule remediation.

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-2020-3552

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 0.05% 0.48% +0.43%
2 2023-03-07 0.89% 0.05% -0.83%
3 2022-04-01 0.89%

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-3552

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.4 3.1 HIGH
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 4.0 [email protected]
7.4 3.0 HIGH
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 4.0 [email protected]
6.1 2.0 MEDIUM
AV:A/AC:L/Au:N/C:N/I:N/A:C Click to expand
Access vector (AV:A)
Requires access to an adjacent network segment.
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:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
6.5 6.9 [email protected]

Weakness enumeration for CVE-2020-3552

Affected software / configurations for CVE-2020-3552

Vendor Product Version Raw CPE
cisco wireless_lan_controller >= 8.6, < 8.10.105.0 cpe:2.3:o:cisco:wireless_lan_controller:*:*:*:*:*:*:*:*
cisco business_access_points >= 10.0, < 10.1.1.0 cpe:2.3:a:cisco:business_access_points:*:*:*:*:*:*:*:*
cisco access_points < 16.12.4a cpe:2.3:o:cisco:access_points:*:*:*:*:*:*:*:*
cisco aironet_access_point_software 8.10\(1.255\) cpe:2.3:a:cisco:aironet_access_point_software:8.10\(1.255\):*:*:*:*:*:*:*

References for CVE-2020-3552

cvelogic Threat Intelligence