CVE-2022-20728 | Cisco Access Points VLAN Bypass from Native VLAN Vulnerability

A vulnerability in the client forwarding code of multiple Cisco Access Points (APs) could allow an unauthenticated, adjacent attacker to inject packets from the native VLAN to clients within nonnative VLANs on an affected device. This vulnerability is due to a logic error on the AP that forwards packets that are destined to a wireless client if they are received on the native VLAN. An attacker could exploit this vulnerability by obtaining access to the native VLAN and directing traffic directly to the client through their MAC/IP combination. A successful exploit could allow the attacker to bypass VLAN separation and potentially also bypass any Layer 3 protection mechanisms that are deployed.

Published: 2022-09-30 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-20728 is rated Low Risk (24.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.24%). 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-2022-20728

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 0.13% 0.24% +0.11%
2 2025-10-07 0.04% 0.13% +0.08%
3 2023-03-07 — 0.04% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-20728

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.7 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N 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:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 [email protected]
4.7 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N 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:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 [email protected]

Weakness enumeration for CVE-2022-20728

Affected software / configurations for CVE-2022-20728

Vendor Product Version Raw CPE
cisco aironet_1542d_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1542d_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1542i_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1542i_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1562i_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1562i_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1562e_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1562e_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1562d_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1562d_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1815i_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1815i_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1815m_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1815m_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1815t_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1815t_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1815w_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1815w_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1830_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1830_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1840_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1840_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1850e_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1850e_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_1850i_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_1850i_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_2800i_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_2800i_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_2800e_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_2800e_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_3800i_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_3800i_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_3800e_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_3800e_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_3800p_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_3800p_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco aironet_4800_firmware 017.006\(001\) cpe:2.3:o:cisco:aironet_4800_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco catalyst_9105ax_firmware 017.006\(001\) cpe:2.3:o:cisco:catalyst_9105ax_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco catalyst_9115ax_firmware 017.006\(001\) cpe:2.3:o:cisco:catalyst_9115ax_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco catalyst_9117ax_firmware 017.006\(001\) cpe:2.3:o:cisco:catalyst_9117ax_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco catalyst_9120ax_firmware 017.006\(001\) cpe:2.3:o:cisco:catalyst_9120ax_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco catalyst_9124ax_firmware 017.006\(001\) cpe:2.3:o:cisco:catalyst_9124ax_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco catalyst_9130ax_firmware 017.006\(001\) cpe:2.3:o:cisco:catalyst_9130ax_firmware:017.006\(001\):*:*:*:*:*:*:*
cisco catalyst_iw6300_firmware 017.006\(001\) cpe:2.3:o:cisco:catalyst_iw6300_firmware:017.006\(001\):*:*:*:*:*:*:*

References for CVE-2022-20728

cvelogic Threat Intelligence