#VU56116 Buffer overflow in Cisco Systems, Inc products - CVE-2021-1590

Vulnerability identifier: #VU56116

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-1590

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco NX-OS
Operating systems & Components / Operating system
Cisco MDS 9000 Series Multilayer Switches
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 5600 Platform Switches
Hardware solutions / Routers & switches, VoIP, GSM, etc
Cisco Nexus 6000 Series Switches
Hardware solutions / Routers & switches, VoIP, GSM, etc
Cisco 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 6200 Series Fabric Interconnects
Hardware solutions / Routers & switches, VoIP, GSM, etc
UCS 6300 Series Fabric Interconnects
Hardware solutions / Routers & switches, VoIP, GSM, etc

Vendor: Cisco Systems, Inc

Description

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

The vulnerability exists due to a boundary error in the implementation of the system login block-for command. A remote attacker can trigger memory corruption and cause a denial of service condition on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco NX-OS: All versions

Cisco MDS 9000 Series Multilayer Switches: 7.0.3 I4.0.116

Cisco Nexus 3000 Series Switches: 7.0.3 I4.0.116

Nexus 5500 Platform Switches: 7.3.7 N1.1b

Nexus 5600 Platform Switches: 7.3.7 N1.1b

Cisco Nexus 6000 Series Switches: 7.3.7 N1.1b

Cisco Nexus 7000 Series Switches: 7.0.3 I4.0.116

Cisco Nexus 9000 Series Switches NX-OS Mode: 7.0.3 I4.0.116

UCS 6200 Series Fabric Interconnects: 4.0 - 4.1

UCS 6300 Series Fabric Interconnects: 4.0 - 4.1

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External links
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-login-blockfor-RwjGVEcu

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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.