CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:N/I:C/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
EPSS
Percentile
9.9%
A vulnerability in the system shell for Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an authenticated, local attacker to use symbolic links to overwrite system files. These system files may be sensitive and should not be overwritable by non-root users. The attacker would need valid device credentials. The vulnerability is due to incorrect symbolic link verification of directory paths when they are used in the system shell. An attacker could exploit this vulnerability by authenticating to the device and providing crafted user input to specific symbolic link CLI commands. Successful exploitation could allow the attacker to overwrite system files that should be restricted. This vulnerability has been fixed in software version 14.1(1i).
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(501300);
script_version("1.1");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/07/26");
script_cve_id("CVE-2019-1836");
script_name(english:"Cisco Nexus 9000 Series Fabric Switches Application Centric Infrastructure Mode Symbolic Link Path Traversal (CVE-2019-1836)");
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 system shell for Cisco Nexus 9000 Series Fabric
Switches in Application Centric Infrastructure (ACI) mode could allow
an authenticated, local attacker to use symbolic links to overwrite
system files. These system files may be sensitive and should not be
overwritable by non-root users. The attacker would need valid device
credentials. The vulnerability is due to incorrect symbolic link
verification of directory paths when they are used in the system
shell. An attacker could exploit this vulnerability by authenticating
to the device and providing crafted user input to specific symbolic
link CLI commands. Successful exploitation could allow the attacker to
overwrite system files that should be restricted. This vulnerability
has been fixed in software version 14.1(1i).
This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.");
script_set_attribute(attribute:"see_also", value:"http://www.securityfocus.com/bid/108150");
# https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190501-fabric-traversal
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b8edbc36");
script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:N/I:C/A:C");
script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/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-2019-1836");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_cwe_id(59);
script_set_attribute(attribute:"vuln_publication_date", value:"2019/05/03");
script_set_attribute(attribute:"patch_publication_date", value:"2019/05/03");
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:14.0%283d%29");
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:14.0%283d%29" :
{"versionEndIncluding" : "14.0%283d%29", "versionStartIncluding" : "14.0%283d%29", "family" : "NXOS"}
};
tenable_ot::cve::compare_and_report(asset:asset, cpes:vuln_cpes, severity:SECURITY_WARNING);
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:N/I:C/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
EPSS
Percentile
9.9%