Out-of-bounds write in Cisco Unidirectional Link Detection feature in FXOS and NX-OS Software

1) Out-of-bounds write

EUVDB-ID: #VU50951

Risk: Medium

CVSSv3.1: 7.7 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-1368

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing untrusted input in the Unidirectional Link Detection (UDLD) feature. A remote attacker on the local network can trigger out-of-bounds write and execute arbitrary code on the target system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Cisco Firepower 4100 Series Next-Generation Firewall: 2.8 - 2.9

Firepower 9300 Series Security Appliances: 2.8 - 2.9

UCS 6200 Series Fabric Interconnects: 4.0 - 4.1

UCS 6300 Series Fabric Interconnects: 4.0 - 4.1

UCS 6400 Series Fabric Interconnects: 4.0 - 4.1

Cisco MDS 9000 Series Multilayer Switches: before 7.0.3 I7.9

Cisco Nexus 3000 Series Switches: before 7.0.3 I7.9

Nexus 5500 Platform Switches: before 7.3.8 N1.1

Nexus 5600 Platform Switches: before 7.3.8 N1.1

Nexus 6000 Series Switches: before 7.3.8 N1.1

Nexus 7000 Series Switches: before 8.2.5

Cisco Nexus 9000 Series Switches NX-OS Mode: before 7.0.3 I7.9

External links

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-udld-rce-xetH6w35

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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