Vulnerability Description
A vulnerability in Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) Mode could allow an unauthenticated, remote attacker to cause a queue wedge on a leaf switch, which could result in critical control plane traffic to the device being dropped. This could result in one or more leaf switches being removed from the fabric. This vulnerability is due to mishandling of ingress TCP traffic to a specific port. An attacker could exploit this vulnerability by sending a stream of TCP packets to a specific port on a Switched Virtual Interface (SVI) configured on the device. A successful exploit could allow the attacker to cause a specific packet queue to queue network buffers but never process them, leading to an eventual queue wedge. This could cause control plane traffic to be dropped, resulting in a denial of service (DoS) condition where the leaf switches are unavailable. Note: This vulnerability requires a manual intervention to power-cycle the device to recover.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Nx-Os | 13.2\(3n\) |
| Cisco | Nexus 93120Tx | - |
| Cisco | Nexus 93128Tx | - |
| Cisco | Nexus 9332Pq | - |
| Cisco | Nexus 9372Px | - |
| Cisco | Nexus 9372Px-E | - |
| Cisco | Nexus 9372Tx | - |
| Cisco | Nexus 9372Tx-E | - |
| Cisco | Nexus 9396Px | - |
| Cisco | Nexus 9396Tx | - |
Related Weaknesses (CWE)
References
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nVendor Advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nVendor Advisory
FAQ
What is CVE-2021-1523?
CVE-2021-1523 is a vulnerability with a CVSS score of 8.6 (HIGH). A vulnerability in Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) Mode could allow an unauthenticated, remote attacker to cause a queue wedge on a leaf switch, whi...
How severe is CVE-2021-1523?
CVE-2021-1523 has been rated HIGH with a CVSS base score of 8.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-1523?
Check the references section above for vendor advisories and patch information. Affected products include: Cisco Nx-Os, Cisco Nexus 93120Tx, Cisco Nexus 93128Tx, Cisco Nexus 9332Pq, Cisco Nexus 9372Px.