Cisco FXOS Software Unidirectional Link Detection DoS / Code Execution (cisco-sa-nxos-udld-rce-xetH6w35)

high Nessus Plugin ID 149718
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The remote device is missing a vendor-supplied security patch.


An arbitrary code execution or denial of service (DoS) vulnerability exists in Unidirectional Link Detection (UDLD) feature of Cisco FXOS Software due to insufficient input validation. An unauthenticated, adjacent attacker can exploit this issue by sending crafted Cisco UDLD protocol packets to a directly connected, affected device, to cause the device to reload, resulting in a DoS condition or arbitrary code execution.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.


Upgrade to the relevant fixed version referenced in Cisco bug IDs CSCvv96092 and CSCvw38984

See Also

Plugin Details

Severity: High

ID: 149718

File Name: cisco-sa-fxos-udld-rce-xetH6w35.nasl

Version: 1.4

Type: local

Family: CISCO

Published: 5/19/2021

Updated: 5/20/2021

Dependencies: cisco_enumerate_firepower.nbin

Configuration: Enable paranoid mode

Risk Information

CVSS Score Source: CVE-2021-1368


Risk Factor: Medium

Score: 5.9


Risk Factor: Medium

Base Score: 4.9

Temporal Score: 3.6

Vector: AV:A/AC:M/Au:S/C:P/I:P/A:P

Temporal Vector: E:U/RL:OF/RC:C


Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:cisco:fxos

Required KB Items: installed_sw/FXOS, Settings/ParanoidReport

Exploit Ease: No known exploits are available

Patch Publication Date: 2/24/2021

Vulnerability Publication Date: 2/24/2021

Reference Information

CVE: CVE-2021-1368

IAVA: 2021-A-0113

CISCO-SA: cisco-sa-nxos-udld-rce-xetH6w35

CISCO-BUG-ID: CSCvv96092, CSCvw38984

CWE: 787