medium
5.3
CWE
787
Advisory Published
Updated

CVE-2021-1590: Cisco NX-OS Software system login block-for Denial of Service Vulnerability

First published: Wed Aug 25 2021(Updated: )

A vulnerability in the implementation of the system login block-for command for Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a login process to unexpectedly restart, causing a denial of service (DoS) condition. This vulnerability is due to a logic error in the implementation of the system login block-for command when an attack is detected and acted upon. An attacker could exploit this vulnerability by performing a brute-force login attack on an affected device. A successful exploit could allow the attacker to cause a login process to reload, which could result in a delay during authentication to the affected device.

Credit: ykramarz@cisco.com

Affected SoftwareAffected VersionHow to fix
Cisco NX-OS=7.0\(3\)i4\(0.116\)
Cisco NX-OS=7.3\(7\)n1\(1b\)
Cisco Nexus 3000
Cisco Nexus 3048 Firmware
Cisco Nexus 31108PC-V Firmware
Cisco Nexus 31108TC-V Firmware
Cisco Nexus 31128PQ
Cisco Nexus 3132C-Z Firmware
Cisco Nexus 3132Q-V Firmware
Cisco Nexus 3132Q-X/3132Q-XL
Cisco Nexus 3164Q Firmware
Cisco Nexus 3172PQ/PQ-XL
Cisco Nexus 3172TQ-XL Firmware
Cisco Nexus 3232C
Cisco Nexus 3264C-E Firmware
Cisco Nexus 3264Q Firmware
Cisco Nexus 3408-S Firmware
Cisco Nexus 34180YC Firmware
Cisco Nexus 3432D-S Firmware
Cisco Nexus 3464C Firmware
Cisco Nexus 3524-x/xl
Cisco Nexus 3548-x/xl
Cisco Nexus 36180YC-R Firmware
Cisco Nexus 3636C-R Firmware
Cisco Nexus 5548P Firmware
Cisco Nexus 5548UP Firmware
Cisco Nexus 5596T Firmware
Cisco Nexus 5596UP Firmware
Cisco 56128p
Cisco Nexus 5624Q Firmware
Cisco Nexus 5648Q Firmware
Cisco Nexus 5672UP-16G
Cisco Nexus 5672UP-16G Firmware
Cisco Nexus 5696Q Firmware
Cisco Nexus 6001 Firmware
Cisco Nexus 6004 Firmware
Cisco Nexus 7000
Cisco Nexus 7000
Cisco Nexus 7000
Cisco Nexus 7000 9-Slot Firmware
Cisco Nexus 7000 Supervisor 1 Firmware
Cisco Nexus 7000 Supervisor 2E
Cisco Nexus 7000 Supervisor 2E Firmware
Cisco Nexus 7004 Firmware
Cisco Nexus 7009 Firmware
Cisco Nexus 7010 Firmware
Cisco Nexus 7018 Firmware
Cisco Nexus 7700 series
Cisco Nexus 7700 series
Cisco Nexus 7700 series
Cisco Nexus 7700 series
Cisco Nexus 7700 6-slot
Cisco Nexus 7700 Supervisor 2E Firmware
Cisco Nexus 7700 Supervisor 3E Firmware
Cisco Nexus 7702 firmware
Cisco Nexus 7706 firmware
Cisco Nexus 7710 Firmware
Cisco Nexus 7718 firmware
Cisco NX-OS Nexus 9000 Series
Cisco Nexus 92160YC Switch
Cisco Nexus 92300YC Firmware
Cisco Nexus 92304QC Switch
Cisco Nexus 92348GC-X Switch
Cisco Nexus 9236C Switch
Cisco Nexus 9272Q Switch
Cisco Nexus
Cisco Nexus 93108TC-EX-24 Firmware
Cisco Nexus 93108TC-FX Switch
Cisco Nexus 93108TC-FX Switch
Cisco Nexus 93108TC-FX3P Firmware
Cisco Nexus 93120TX Firmware
Cisco Nexus 93128 Firmware
Cisco Nexus 9316D-GX Firmware
Cisco Nexus 93180LC-EX Switch
Cisco Nexus 93180YC-EX-24
Cisco Nexus 93180YC-EX-24 Firmware
Cisco Nexus 93180YC-FX Firmware
Cisco Nexus 93180YC-FX-24 Firmware
Cisco Nexus 93180YC-FX3 Firmware
Cisco Nexus 93180YC-FX3S Firmware
Cisco Nexus 93216TC-FX2 Firmware
Cisco Nexus 93240YC-FX2 Firmware
Cisco Nexus 9332C Firmware
Cisco Nexus 9332PQ Firmware
Cisco Nexus 93360YC-FX2
Cisco Nexus 9336C-FX2 Firmware
Cisco Nexus 9336C-FX2-E Firmware
Cisco Nexus 9348GC-FXP Firmware
Cisco Nexus 93600CD-GX Firmware
Cisco Nexus 9364c-h1
Cisco Nexus 9364C-GX Firmware
Cisco Nexus 9372PX-E
Cisco Nexus 9372PX-E Firmware
Cisco Nexus 9372TX
Cisco Nexus 9372TX-E Switch
Cisco Nexus 9396PX Firmware
Cisco Nexus 9396TX Firmware
Cisco Nexus 9508
Cisco Unified Computing System software<4.0\(4m\)
Cisco Unified Computing System software>=4.1<4.1\(3d\)
Cisco Unified Computing System software
Cisco Unified Computing System 6296UP
Cisco Unified Computing System
Cisco Unified Computing System 6332
Cisco Unified Computing System software

Remedy

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-login-blockfor-RwjGVEcu

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2021-1590?

    CVE-2021-1590 has been rated as a high severity vulnerability due to its potential to cause a denial of service (DoS).

  • How do I fix CVE-2021-1590?

    To fix CVE-2021-1590, update your Cisco NX-OS to the latest patched version as recommended by Cisco's advisory.

  • Which Cisco NX-OS versions are affected by CVE-2021-1590?

    CVE-2021-1590 affects Cisco NX-OS versions 7.0(3)i4(0.116) and 7.3(7)n1(1b).

  • Is there any workaround for CVE-2021-1590?

    No specific workaround is provided for CVE-2021-1590; applying the latest updates is the best course of action.

  • Can CVE-2021-1590 be exploited remotely?

    Yes, CVE-2021-1590 can be exploited by an unauthenticated remote attacker.

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