// For flags

CVE-2021-1523

Cisco Nexus 9000 Series Fabric Switches ACI Mode Queue Wedge Denial of Service Vulnerability

Severity Score

8.6
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Attend
*SSVC
Descriptions

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.

Una vulnerabilidad en Cisco Nexus 9000 Series Fabric Switches en el Modo Application Centric Infrastructure (ACI), podría permitir a un atacante remoto no autenticado causar un acuñamiento de queues en un switch de hoja, que podría resultar en una caída del tráfico crítico del plano de control en el dispositivo. Esto podría dar lugar a que uno o más switches de hoja sean eliminados de la estructura. Esta vulnerabilidad es debido a un manejo inapropiado del tráfico TCP de entrada a un puerto específico. Un atacante podría explotar esta vulnerabilidad mediante el envío de un flujo de paquetes TCP a un puerto específico en una Switched Virtual Interface configurada en el dispositivo. Una explotación con éxito podría permitir al atacante causar que una queue de paquetes específica ponga en queue los búferes de red pero nunca los procese, conllevando a un eventual acuñamiento de queues. Esto podría causar que el tráfico del plano de control se caiga, resultando en una condición de denegación de servicio (DoS) donde los switches de la hoja no están disponibles. Nota: Esta vulnerabilidad requiere una intervención manual para apagar el dispositivo y recuperarlo.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:Attend
Exploitation
None
Automatable
Yes
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2020-11-13 CVE Reserved
  • 2021-08-25 CVE Published
  • 2024-05-10 EPSS Updated
  • 2024-11-07 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-772: Missing Release of Resource after Effective Lifetime
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
13.2\(3n\)
Search vendor "Cisco" for product "Nx-os" and version "13.2\(3n\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 93120tx
Search vendor "Cisco" for product "Nexus 93120tx"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
13.2\(3n\)
Search vendor "Cisco" for product "Nx-os" and version "13.2\(3n\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 93128tx
Search vendor "Cisco" for product "Nexus 93128tx"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
13.2\(3n\)
Search vendor "Cisco" for product "Nx-os" and version "13.2\(3n\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9332pq
Search vendor "Cisco" for product "Nexus 9332pq"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
13.2\(3n\)
Search vendor "Cisco" for product "Nx-os" and version "13.2\(3n\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9372px
Search vendor "Cisco" for product "Nexus 9372px"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
13.2\(3n\)
Search vendor "Cisco" for product "Nx-os" and version "13.2\(3n\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9372px-e
Search vendor "Cisco" for product "Nexus 9372px-e"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
13.2\(3n\)
Search vendor "Cisco" for product "Nx-os" and version "13.2\(3n\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9372tx
Search vendor "Cisco" for product "Nexus 9372tx"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
13.2\(3n\)
Search vendor "Cisco" for product "Nx-os" and version "13.2\(3n\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9372tx-e
Search vendor "Cisco" for product "Nexus 9372tx-e"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
13.2\(3n\)
Search vendor "Cisco" for product "Nx-os" and version "13.2\(3n\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9396px
Search vendor "Cisco" for product "Nexus 9396px"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
13.2\(3n\)
Search vendor "Cisco" for product "Nx-os" and version "13.2\(3n\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9396tx
Search vendor "Cisco" for product "Nexus 9396tx"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
14.2\(4i\)
Search vendor "Cisco" for product "Nx-os" and version "14.2\(4i\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 93120tx
Search vendor "Cisco" for product "Nexus 93120tx"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
14.2\(4i\)
Search vendor "Cisco" for product "Nx-os" and version "14.2\(4i\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 93128tx
Search vendor "Cisco" for product "Nexus 93128tx"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
14.2\(4i\)
Search vendor "Cisco" for product "Nx-os" and version "14.2\(4i\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9332pq
Search vendor "Cisco" for product "Nexus 9332pq"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
14.2\(4i\)
Search vendor "Cisco" for product "Nx-os" and version "14.2\(4i\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9372px
Search vendor "Cisco" for product "Nexus 9372px"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
14.2\(4i\)
Search vendor "Cisco" for product "Nx-os" and version "14.2\(4i\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9372px-e
Search vendor "Cisco" for product "Nexus 9372px-e"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
14.2\(4i\)
Search vendor "Cisco" for product "Nx-os" and version "14.2\(4i\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9372tx
Search vendor "Cisco" for product "Nexus 9372tx"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
14.2\(4i\)
Search vendor "Cisco" for product "Nx-os" and version "14.2\(4i\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9372tx-e
Search vendor "Cisco" for product "Nexus 9372tx-e"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
14.2\(4i\)
Search vendor "Cisco" for product "Nx-os" and version "14.2\(4i\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9396px
Search vendor "Cisco" for product "Nexus 9396px"
--
Safe
Cisco
Search vendor "Cisco"
Nx-os
Search vendor "Cisco" for product "Nx-os"
14.2\(4i\)
Search vendor "Cisco" for product "Nx-os" and version "14.2\(4i\)"
-
Affected
in Cisco
Search vendor "Cisco"
Nexus 9396tx
Search vendor "Cisco" for product "Nexus 9396tx"
--
Safe