Vulnerability identifier: #VU50942

Vulnerability risk: Medium

CVSSv3.1: 5.1 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-1229

CWE-ID: CWE-401

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco MDS 9000 Series Multilayer Switches
Hardware solutions / Routers & switches, VoIP, GSM, etc
Nexus 1000V Switch for Microsoft Hyper-V
Hardware solutions / Routers & switches, VoIP, GSM, etc
Nexus 1000V Switch for VMware vSphere
Hardware solutions / Routers & switches, VoIP, GSM, etc
Cisco Nexus 3000 Series Switches
Hardware solutions / Routers & switches, VoIP, GSM, etc
Nexus 5500 Platform Switches
Hardware solutions / Routers & switches, VoIP, GSM, etc
Nexus 6000 Series Switches
Hardware solutions / Routers & switches, VoIP, GSM, etc
Nexus 7000 Series Switches
Hardware solutions / Routers & switches, VoIP, GSM, etc
Cisco Nexus 9000 Series Switches in ACI Mode
Hardware solutions / Routers & switches, VoIP, GSM, etc
Cisco Nexus 9000 Series Switches NX-OS Mode
Hardware solutions / Routers & switches, VoIP, GSM, etc
Nexus 1000 Virtual Edge for VMware vSphere
Server applications / Other server solutions

Vendor: Cisco Systems, Inc

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

The vulnerability exists due to improper error handling when an IPv6-configured interface receives a specific type of ICMPv6 packet. A remote attacker can force the application to leak memory and cause a denial of service condition on the target system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Cisco MDS 9000 Series Multilayer Switches: 8.4.3.53

Nexus 1000 Virtual Edge for VMware vSphere: 5.2.1 SV5.1.3a

Nexus 1000V Switch for Microsoft Hyper-V: 5.2.1 SV5.1.3a

Nexus 1000V Switch for VMware vSphere: 5.2.1 SV5.1.3a

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fxos-nxos-icmpv6-dos-YD55jVCq
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvv24541
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvv96592
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvv96593

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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.