Memory leak in Cisco Systems, Inc products - CVE-2021-1387

Vulnerability identifier: #VU50943

CSH Severity: Medium

CVSS v4: 8.7 [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]

CVE-ID: CVE-2021-1387

CWE-ID: CWE-401

Exploitation vector: Remote access

Exploit availability: No public exploit available

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.

Cisco Nexus 3000 Series Switches
Cisco Nexus 9000 Series Switches NX-OS Mode
Nexus 7000 Series Switches
Nexus 5500 Platform Switches
Nexus 5600 Platform Switches
Nexus 6000 Series Switches
UCS 6400 Series Fabric Interconnects

Install updates from vendor's website.

Cisco Nexus 3000 Series Switches - update to 7.0.3 I7.9
Cisco Nexus 9000 Series Switches NX-OS Mode - update to 7.0.3 I7.9
Nexus 7000 Series Switches - addressed in versions 7.3.5 D1.1, 8.2.5
Nexus 5500 Platform Switches - update to 7.3.8 N1.1
Nexus 5600 Platform Switches - update to 7.3.8 N1.1
Nexus 6000 Series Switches - update to 7.3.8 N1.1
UCS 6400 Series Fabric Interconnects - update to 8.4.2a

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

• Denial of service in Cisco NX-OS Software IPv6