CVSS2
Attack Vector
ADJACENT_NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:A/AC:M/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
ADJACENT
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS
Percentile
25.0%
A vulnerability in the Unidirectional Link Detection (UDLD) feature of Cisco FXOS Software, Cisco IOS Software, Cisco IOS XE Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload. This vulnerability is due to improper input validation of the UDLD packets. An attacker could exploit this vulnerability by sending specifically crafted UDLD packets to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. Note: The UDLD feature is disabled by default, and the conditions to exploit this vulnerability are strict. An attacker must have full control of a directly connected device. On Cisco IOS XR devices, the impact is limited to the reload of the UDLD process.
This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.
#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##
include('compat.inc');
if (description)
{
script_id(501358);
script_version("1.2");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/19");
script_cve_id("CVE-2021-34714");
script_name(english:"Cisco Multiple Operating Systems Unidirectional Link Detection Denial of Service (CVE-2021-34714)");
script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
script_set_attribute(attribute:"description", value:
"A vulnerability in the Unidirectional Link Detection (UDLD) feature of
Cisco FXOS Software, Cisco IOS Software, Cisco IOS XE Software, Cisco
IOS XR Software, and Cisco NX-OS Software could allow an
unauthenticated, adjacent attacker to cause an affected device to
reload. This vulnerability is due to improper input validation of the
UDLD packets. An attacker could exploit this vulnerability by sending
specifically crafted UDLD packets to an affected device. A successful
exploit could allow the attacker to cause the affected device to
reload, resulting in a denial of service (DoS) condition. Note: The
UDLD feature is disabled by default, and the conditions to exploit
this vulnerability are strict. An attacker must have full control of a
directly connected device. On Cisco IOS XR devices, the impact is
limited to the reload of the UDLD process.
This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.");
# https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-nxos-xr-udld-dos-W5hGHgtQ
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?bec5ced8");
script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
script_set_cvss_base_vector("CVSS2#AV:A/AC:M/Au:N/C:N/I:N/A:C");
script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-34714");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_cwe_id(20);
script_set_attribute(attribute:"vuln_publication_date", value:"2021/09/23");
script_set_attribute(attribute:"patch_publication_date", value:"2021/09/23");
script_set_attribute(attribute:"plugin_publication_date", value:"2023/07/25");
script_set_attribute(attribute:"plugin_type", value:"remote");
script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nx-os:3");
script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nx-os:7");
script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nx-os:8");
script_set_attribute(attribute:"generated_plugin", value:"former");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Tenable.ot");
script_copyright(english:"This script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("tenable_ot_api_integration.nasl");
script_require_keys("Tenable.ot/Cisco");
exit(0);
}
include('tenable_ot_cve_funcs.inc');
get_kb_item_or_exit('Tenable.ot/Cisco');
var asset = tenable_ot::assets::get(vendor:'Cisco');
var vuln_cpes = {
"cpe:/o:cisco:nx-os:8" :
{"versionEndIncluding" : "8.4%283.115%29", "family" : "NXOS"},
"cpe:/o:cisco:nx-os:7.0%283%29" :
{"versionEndIncluding" : "7.0%283%29i7%289%29", "family" : "NXOS"},
"cpe:/o:cisco:nx-os:7.3%288%29" :
{"versionEndIncluding" : "7.3%288%29n1%281%29", "family" : "NXOS"},
"cpe:/o:cisco:nx-os:3" :
{"versionEndIncluding" : "3.2%283o%29a", "family" : "NXOS"}
};
tenable_ot::cve::compare_and_report(asset:asset, cpes:vuln_cpes, severity:SECURITY_WARNING);
CVSS2
Attack Vector
ADJACENT_NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:A/AC:M/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
ADJACENT
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS
Percentile
25.0%