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.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
4.7
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.
- Record
CVE-2022-20728- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-284
- Updated
- 2026-11-02
EUVDEUVD-2022-25978
4.7
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.
- Record
EUVD-2022-25978- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-66v9-vq83-62h5
4.7
A vulnerability in the client forwarding code of multiple Cisco Access Points (APs) could allow...
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.
- Record
GHSA-66v9-vq83-62h5- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N - Updated
- 2026-11-02
NVD
4.7
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.
- Record
CVE-2022-20728- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-284
- Updated
- 2026-11-02
Affected products
- cisco aironet 1542d firmware
- cisco aironet 1542i firmware
- cisco aironet 1562d firmware
- cisco aironet 1562e firmware
- cisco aironet 1562i firmware
- cisco aironet 1815i firmware
- cisco aironet 1815m firmware
- cisco aironet 1815t firmware
- cisco aironet 1815w firmware
- cisco aironet 1830 firmware
- cisco aironet 1840 firmware
- cisco aironet 1850e firmware
Show 15 moreShow less
- cisco aironet 1850i firmware
- cisco aironet 2800e firmware
- cisco aironet 2800i firmware
- cisco aironet 3800e firmware
- cisco aironet 3800i firmware
- cisco aironet 3800p firmware
- cisco aironet 4800 firmware
- cisco catalyst 9105ax firmware
- cisco catalyst 9115ax firmware
- cisco catalyst 9117ax firmware
- cisco catalyst 9120ax firmware
- cisco catalyst 9124ax firmware
- cisco catalyst 9130ax firmware
- cisco catalyst iw6300 firmware
- cisco aironet access point software (ios xe controller)
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2022-20728 is a medium vulnerability (CVSS 4.7) in Cisco Aironet 1542d Firmware, published September 30, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.27%, the 18th percentile. No source names a fixed version.