medium4.7
CVE-2021-27853
Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers.
Impact
Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Ieee | Ieee 802.2 | through 802.2h-1997 |
| Ietf | P802.1q | through d1.0 |
| Cisco | Catalyst 6503-E Firmware | Version 15.5\(01.01.85\)sy07 |
| Cisco | Catalyst 6504-E Firmware | Version 15.5\(01.01.85\)sy07 |
| Cisco | Catalyst 6506-E Firmware | Version 15.5\(01.01.85\)sy07 |
| Cisco | Catalyst 6509-E Firmware | Version 15.5\(01.01.85\)sy07 |
| Cisco | Catalyst 6509-Neb-A Firmware | Version 15.5\(01.01.85\)sy07 |
| Cisco | Catalyst 6509-V-E Firmware | Version 15.5\(01.01.85\)sy07 |
| Cisco | Catalyst 6513-E Firmware | Version 15.5\(01.01.85\)sy07 |
| Cisco | Catalyst 6807-Xl Firmware | Version 15.5\(01.01.85\)sy07 |
| Cisco | Catalyst 6840-X Firmware | Version 15.5\(01.01.85\)sy07 |
| Cisco | Catalyst 6880-X Firmware | Version 15.5\(01.01.85\)sy07 |
Weakness classification
References
- NVD record
- CVE.org record
- https://blog.champtar.fr/VLAN0_LLC_SNAP/
- https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/
- https://kb.cert.org/vuls/id/855201
- https://standards.ieee.org/ieee/802.1Q/10323/
- https://standards.ieee.org/ieee/802.2/1048/
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-VU855201-J3z8CKTX
- https://blog.champtar.fr/VLAN0_LLC_SNAP/
- https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/
- https://kb.cert.org/vuls/id/855201
- https://standards.ieee.org/ieee/802.1Q/10323/
- https://standards.ieee.org/ieee/802.2/1048/
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-VU855201-J3z8CKTX
- https://www.kb.cert.org/vuls/id/855201