Denial of service in Cisco FXOS, NX-OS Software and Cisco Fabric Services

1) NULL pointer dereference

EUVDB-ID: #VU46104

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-3517

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in the Cisco Fabric Services component . A remote attacker can send malicious Cisco Fabric Services messages and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Cisco FXOS: 1.1 - 2.2

Cisco NX-OS: All versions

Cisco Firepower 4100 Series Next-Generation Firewall: 2.7.1.122

Cisco Firepower 9300 Security Appliance: 2.7.1.122

Cisco MDS 9000 Series Multilayer Switches: 8.4.1

Cisco Nexus 3000 Series Switches: before 8.2.6

Cisco Nexus 5500 Series Switches: 7.3.7 N1.0.786

Cisco Nexus 5600 Series Switches: 7.3.7 N1.0.786

Cisco Nexus 6000 Series Switches: 7.3.7 N1.0.786

Cisco Nexus 7000 Series Switches: 8.4.1

Cisco Nexus 9000 Series Switches NX-OS Mode: before 8.2.6

UCS 6200 Series Fabric Interconnects: 4.1.1

UCS 6300 Series Fabric Interconnects: 4.1.1

UCS 6400 Series Fabric Interconnects: 4.1.1

CPE2.3

• cpe:2.3:o:cisco_systems:cisco_fxos:1.1:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_fxos:2.0:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_fxos:2.1:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_nx-os:*:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_firepower_4100_series_next-generation_firewall:2.7.1.122:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_firepower_9300_security_appliance:2.7.1.122:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_mds_9000_series_multilayer_switches:8.4.1:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_nexus_3000_series_switches:*:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_nexus_5500_series_switches:7.3.7 N1.0.786:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_nexus_5600_series_switches:7.3.7 N1.0.786:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_nexus_6000_series_switches:7.3.7 N1.0.786:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_nexus_7000_series_switches:8.4.1:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_nexus_9000_series_switches_nx-os_mode:*:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:ucs_6200_series_fabric_interconnects:4.1.1:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:ucs_6300_series_fabric_interconnects:4.1.1:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:ucs_6400_series_fabric_interconnects:4.1.1:*:*:*:*:*:*:*

External links

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fxos-nxos-cfs-dos-dAmnymbd

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.