CVE-2021-1368

CVSS V2 Medium 4.9 CVSS V3 High 8.8

Description

A vulnerability in the Unidirectional Link Detection (UDLD) feature of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code with administrative privileges or cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending crafted Cisco UDLD protocol packets to a directly connected, affected device. A successful exploit could allow the attacker to execute arbitrary code with administrative privileges or cause the Cisco UDLD process to crash and restart multiple times, causing the affected device to reload and resulting in a DoS condition. Note: The UDLD feature is disabled by default, and the conditions to exploit this vulnerability are strict. The attacker needs full control of a directly connected device. That device must be connected over a port channel that has UDLD enabled. To trigger arbitrary code execution, both the UDLD-enabled port channel and specific system conditions must exist. In the absence of either the UDLD-enabled port channel or the system conditions, attempts to exploit this vulnerability will result in a DoS condition. It is possible, but highly unlikely, that an attacker could control the necessary conditions for exploitation. The CVSS score reflects this possibility. However, given the complexity of exploitation, Cisco has assigned a Medium Security Impact Rating (SIR) to this vulnerability.

Overview

CVE ID
CVE-2021-1368

Assigner
ykramarz@cisco.com

Vulnerability Status
Analyzed

Published Version
2021-02-24T20:15:13

Last Modified Date
2023-04-20T17:17:59

Weakness Enumerations

CWE	URL
CWE-787	http://cwe.mitre.org/data/definitions/787.html

CPE Configuration (Product)

CPE	Vulnerable	Operator	Version Start	Version End
		AND
cpe:2.3:o:cisco:nx-os:8.4\(3.108\):::::::*	1	OR
cpe:2.3:o:cisco:nx-os:8.4\(3.117\):::::::*	1	OR
cpe:2.3:h:cisco:mds_9148s:-:::::::*	0	OR
cpe:2.3:h:cisco:mds_9250i:-:::::::*	0	OR
cpe:2.3:h:cisco:mds_9706:-:::::::*	0	OR
cpe:2.3:h:cisco:mds_9710:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_7000:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_7700:-:::::::*	0	OR
		AND
cpe:2.3:o:cisco:nx-os:7.0\(3\)i5\(2\):::::::*	1	OR
cpe:2.3:o:cisco:nx-os:7.0\(3\)i7\(9\):::::::*	1	OR
cpe:2.3:o:cisco:nx-os:9.3\(5\):::::::*	1	OR
cpe:2.3:h:cisco:nexus_3048:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_31108pv-v:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_31108tc-v:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_31128pq:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3132c-z:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3132q-v:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3132q-x:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3132q-xl:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3164q:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3172pq:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3172pq-xl:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3232c:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3264c-e:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3264q:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3408-s:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_34180yc:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3432d-s:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3464c:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3524-x:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3524-xl:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3548-x:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3548-xl:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_36180yc-r:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_3636c-r:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9000v:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_92160yc-x:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9221c:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_92300yc:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_92304qc:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_92348gc-x:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9236c:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9272q:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93108tc-ex:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93108tc-ex-24:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93108tc-fx:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93108tc-fx-24:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93120tx:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93128tx:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9316d-gx:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93180lc-ex:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93180yc-ex:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93180yc-ex-24:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93180yc-fx:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93180yc-fx-24:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93180yc-fx3:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93180yc-fx3s:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93216tc-fx2:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93240yc-fx2:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9332pq:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93360yc-fx2:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9336c-fx2:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9336c-fx2-e:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9336pq:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9348gc-fxp:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_93600cd-gx:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9364c:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9364c-gx:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9372px:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9372px-e:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9372tx:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9372tx-e:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9396px:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9396tx:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_9508:-:::::::*	0	OR
		AND
cpe:2.3:o:cisco:nx-os:7.3\(8\)n1\(1\):::::::*	1	OR
cpe:2.3:o:cisco:nx-os:7.3\(9\)n1\(0.823\):::::::*	1	OR
cpe:2.3:h:cisco:nexus_5548p:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_5548up:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_5596t:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_5596up:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_56128p:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_5624q:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_5648q:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_5672up:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_5672up-16g:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_5696q:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_6001:-:::::::*	0	OR
cpe:2.3:h:cisco:nexus_6004:-:::::::*	0	OR
		AND
cpe:2.3:a:cisco:unified_computing_system::::::::	1	OR		4.0\(4i\)
cpe:2.3:a:cisco:unified_computing_system::::::::	1	OR	4.1	4.1\(2c\)
cpe:2.3:h:cisco:ucs_6248up:-:::::::*	0	OR
cpe:2.3:h:cisco:ucs_6296up:-:::::::*	0	OR
cpe:2.3:h:cisco:ucs_6324:-:::::::*	0	OR
cpe:2.3:h:cisco:ucs_6332:-:::::::*	0	OR
cpe:2.3:h:cisco:ucs_6332-16up:-:::::::*	0	OR
cpe:2.3:h:cisco:ucs_64108:-:::::::*	0	OR
cpe:2.3:h:cisco:ucs_6454:-:::::::*	0	OR
		AND
cpe:2.3:o:cisco:fxos:r231:::::::*	1	OR
cpe:2.3:h:cisco:firepower_4110:-:::::::*	0	OR
cpe:2.3:h:cisco:firepower_4112:-:::::::*	0	OR
cpe:2.3:h:cisco:firepower_4115:-:::::::*	0	OR
cpe:2.3:h:cisco:firepower_4120:-:::::::*	0	OR
cpe:2.3:h:cisco:firepower_4125:-:::::::*	0	OR
cpe:2.3:h:cisco:firepower_4140:-:::::::*	0	OR
cpe:2.3:h:cisco:firepower_4145:-:::::::*	0	OR
cpe:2.3:h:cisco:firepower_4150:-:::::::*	0	OR
cpe:2.3:h:cisco:firepower_9300:-:::::::*	0	OR

CVSS Version 2

Version
2.0

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

Access Vector
ADJACENT_NETWORK

Access Compatibility
MEDIUM

Authentication
SINGLE

Confidentiality Impact
PARTIAL

Integrity Impact
PARTIAL

Availability Impact
PARTIAL

Base Score
4.9

Severity
MEDIUM

Exploitability Score
4.4

Impact Score
6.4

CVSS Version 3

Version
3.1

Vector String
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
ADJACENT_NETWORK

Attack Compatibility
LOW

Privileges Required
NONE

User Interaction
NONE

Scope
UNCHANGED

Confidentiality Impact
HIGH

Availability Impact
HIGH

Base Score
8.8

Base Severity
HIGH

Exploitability Score
2.8

Impact Score
5.9

References

Reference URL	Reference Tags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-udld-rce-xetH6w35	Vendor Advisory

Sources

Source Name	Source URL
NIST	https://nvd.nist.gov/vuln/detail/CVE-2021-1368
MITRE	https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-1368

History

Created	Old Value	New Value	Data Type	Notes
2022-05-10 07:21:15				Added to TrackCVE
2022-12-05 22:44:00	psirt@cisco.com	ykramarz@cisco.com	CVE Assigner	updated
2022-12-05 22:44:00	2021-02-24T20:15Z	2021-02-24T20:15:13	CVE Published Date	updated
2022-12-05 22:44:00		2021-03-03T19:22:49	CVE Modified Date	updated
2022-12-05 22:44:00		Analyzed	Vulnerability Status	updated
2023-04-20 21:11:53		2023-04-20T17:17:59	CVE Modified Date	updated