PT-2021-2176 · Cisco · Cisco Nx-Os+2

Published 2021-02-24 · Updated 2023-04-20 · CVE-2021-1368

Positive Technologies (AI Summary)

CVSS v3.1

8.8

High

Base vector

AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Cisco FXOS Software (affected versions not specified) Cisco NX-OS Software (affected versions not specified)

Description The issue is related to insufficient input validation in the Unidirectional Link Detection (UDLD) feature. An unauthenticated, adjacent attacker could exploit this by sending crafted Cisco UDLD protocol packets to a directly connected, affected device. This could allow the attacker to execute arbitrary code with administrative privileges or cause a denial of service (DoS) condition. The UDLD feature is disabled by default, and the conditions to exploit this are strict, requiring full control of a directly connected device connected over a port channel with UDLD enabled.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

DoS

RCE

Memory Corruption

Weakness Enumeration

CWE-787

Related Identifiers

BDU:2021-01083

CVE-2021-1368

Affected Products

Cisco Fxos

Cisco Nx-Os

Cisco Nexus

References · 9

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-udld-rce-xetH6w35 · Vendor Advisory
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-udld-rce-xetH6w35 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-1368 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-1368 · Security Note
• https://bdu.fstec.ru/vul/2021-01083 · Security Note
• https://t.me/cibsecurity/24100 · Telegram Post
• https://t.me/cvenotify/10825 · Telegram Post
• https://t.me/cvenotify/10451 · Telegram Post
• https://t.me/cvenotify/48740 · Telegram Post