Vulnerability identifier: #VU50943

Vulnerability risk: Medium

CVSSv3.1: 7.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-1387

CWE-ID: CWE-401

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco Nexus 3000 Series Switches
Hardware solutions / Routers & switches, VoIP, GSM, etc
Nexus 5500 Platform Switches
Hardware solutions / Routers & switches, VoIP, GSM, etc
Nexus 5600 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 NX-OS Mode
Hardware solutions / Routers & switches, VoIP, GSM, etc
UCS 6400 Series Fabric Interconnects
Hardware solutions / Routers & switches, VoIP, GSM, etc

Vendor:

Description
The vulnerability allows a remote attacker to perform DoS attack on the target system.

The vulnerability exists due memory leak in the network stack. A remote attacker can send multiple crafted IPv6 packets to leak memory and perform denial of service attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-ipv6-netstack-edXPGV7K
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvu11961
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvu77380

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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.