Vulnerability identifier: #VU20539

Vulnerability risk: Medium

CVSSv3.1: 6.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-1963

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco NX-OS
Operating systems & Components / Operating system
Cisco FXOS
Operating systems & Components / Operating system

Vendor: Cisco Systems, Inc

Description

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

The vulnerability exists due to improper validation of Abstract Syntax Notation One (ASN.1)-encoded variables in SNMP packets. A remote authenticated attacker can send a specially crafted SNMP packet to the SNMP daemon and cause the SNMP application to restart multiple times, leading to a system-level restart and a denial of service (DoS) condition.

This vulnerability affects the following products if they have SNMP configured and they are running a vulnerable release of Cisco FXOS or NX-OS Software:

• Firepower 4100 Series
• Firepower 9300 Security Appliances
• MDS 9000 Series Multilayer Switches
• Nexus 1000 Virtual Edge for VMware vSphere
• Nexus 1000V Switch for Microsoft Hyper-V
• Nexus 1000V Switch for VMware vSphere
• Nexus 3000 Series Switches
• Nexus 3500 Platform Switches
• Nexus 3600 Platform Switches
• Nexus 5500 Platform Switches
• Nexus 5600 Platform Switches
• Nexus 6000 Series Switches
• Nexus 7000 Series Switches
• Nexus 7700 Series Switches
• Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode
• Nexus 9000 Series Switches in standalone NX-OS mode
• Nexus 9500 R-Series Switching Platform
• UCS 6200 Series Fabric Interconnects
• UCS 6300 Series Fabric Interconnects
• UCS 6400 Series Fabric Interconnects

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco NX-OS: 5.2 - 14.1

Cisco FXOS: 2.2 - 2.4

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190828-fxnxos-snmp-dos

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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