CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS
Percentile
46.2%
A vulnerability in the rate limiter for Bidirectional Forwarding Detection (BFD) traffic of Cisco NX-OS Software for Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to cause BFD traffic to be dropped on an affected device. This vulnerability is due to a logic error in the BFD rate limiter functionality. An attacker could exploit this vulnerability by sending a crafted stream of traffic through the device. A successful exploit could allow the attacker to cause BFD traffic to be dropped, resulting in BFD session flaps. BFD session flaps can cause route instability and dropped traffic, resulting in a denial of service (DoS) condition.
This vulnerability applies to both IPv4 and IPv6 traffic.
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(501379);
script_version("1.1");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/07/26");
script_cve_id("CVE-2022-20623");
script_name(english:"Cisco Nexus 9000 Series Switches Bidirectional Forwarding Detection Denial of Service (CVE-2022-20623)");
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 rate limiter for Bidirectional Forwarding
Detection (BFD) traffic of Cisco NX-OS Software for Cisco Nexus 9000
Series Switches could allow an unauthenticated, remote attacker to
cause BFD traffic to be dropped on an affected device. This
vulnerability is due to a logic error in the BFD rate limiter
functionality. An attacker could exploit this vulnerability by sending
a crafted stream of traffic through the device. A successful exploit
could allow the attacker to cause BFD traffic to be dropped, resulting
in BFD session flaps. BFD session flaps can cause route instability
and dropped traffic, resulting in a denial of service (DoS) condition.
This vulnerability applies to both IPv4 and IPv6 traffic.
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-nxos-bfd-dos-wGQXrzxn
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?bbf2e13f");
script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
script_set_cvss_base_vector("CVSS2#AV:N/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:N/AC:L/PR:N/UI:N/S:U/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-2022-20623");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_set_attribute(attribute:"vuln_publication_date", value:"2022/02/23");
script_set_attribute(attribute:"patch_publication_date", value:"2022/02/23");
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:10");
script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nx-os:7");
script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nx-os:9");
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:7" :
{"versionEndIncluding" : "7.0%283%29i7%283%29", "versionStartIncluding" : "7.0%283%29i6%282%29", "family" : "NXOS"},
"cpe:/o:cisco:nx-os:9" :
{"versionEndIncluding" : "9.3%288%29", "versionStartIncluding" : "7.0%283%29i6%282%29", "family" : "NXOS"},
"cpe:/o:cisco:nx-os:10" :
{"versionEndIncluding" : "10.2%281%29", "versionStartIncluding" : "10.1%281%29", "family" : "NXOS"}
};
tenable_ot::cve::compare_and_report(asset:asset, cpes:vuln_cpes, severity:SECURITY_HOLE);
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS
Percentile
46.2%