How severe is CVE-2022-20728?

CVE-2022-20728 has a CVSS 3.x base score of 4.7, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2022-20728 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2022-20728?

CVE-2022-20728 primarily affects Cisco Aironet 1542d Firmware. In total, 26 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2022-20728?

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

When was CVE-2022-20728 published?

CVE-2022-20728 was published on 2022-09-30 and last updated on 2026-06-17.

CVE-2022-20728

CVE-2022-20728 is a medium-severity vulnerability in Cisco Aironet 1542d Firmware with a CVSS 3.x base score of 4.7. 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-284.

Key facts

Severity: Medium (CVSS 3.x base score 4.7)
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-284
Affected product: Cisco Aironet 1542d Firmware
Published: 2022-09-30
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2022-20728?: 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.
How severe is CVE-2022-20728?: CVE-2022-20728 has a CVSS 3.x base score of 4.7, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2022-20728 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-20728?: CVE-2022-20728 primarily affects Cisco Aironet 1542d Firmware. In total, 26 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2022-20728?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2022-20728 published?: CVE-2022-20728 was published on 2022-09-30 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apvlan-TDTtb4FY

Affected products (26)

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

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