Vulnerability Monitor

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CVE-2021-1523


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.


Published

2021-08-25T19:15:07.217

Last Modified

2024-11-21T05:44:32.577

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 8.6 (HIGH)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:N/I:N/A:P

  • Access Vector: NETWORK
  • Access Complexity: LOW
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: PARTIAL
Exploitability Score

10.0

Impact Score

2.9

Weaknesses
  • Type: Secondary
    CWE-772
  • Type: Primary
    CWE-772

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Operating System cisco nx-os 13.2\(3n\) Yes
Operating System cisco nx-os 14.2\(4i\) Yes
Hardware cisco nexus_93120tx - No
Hardware cisco nexus_93128tx - No
Hardware cisco nexus_9332pq - No
Hardware cisco nexus_9372px - No
Hardware cisco nexus_9372px-e - No
Hardware cisco nexus_9372tx - No
Hardware cisco nexus_9372tx-e - No
Hardware cisco nexus_9396px - No
Hardware cisco nexus_9396tx - No

References