CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
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
52.6%
A vulnerability in the SSL VPN negotiation process for Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to inefficient direct memory access (DMA) memory management during the negotiation phase of an SSL VPN connection. An attacker could exploit this vulnerability by sending a steady stream of crafted Datagram TLS (DTLS) traffic to an affected device. A successful exploit could allow the attacker to exhaust DMA memory on the device and cause a DoS condition.
Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##
include('compat.inc');
if (description)
{
script_id(168874);
script_version("1.3");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/03/31");
script_cve_id("CVE-2020-3529");
script_xref(name:"CISCO-BUG-ID", value:"CSCvu59817");
script_xref(name:"CISCO-SA", value:"cisco-sa-asaftd-sslvpndma-dos-HRrqB9Yx");
script_xref(name:"IAVA", value:"2020-A-0488-S");
script_name(english:"Cisco Adaptive Security Appliance Software SSL/TLS DoS (cisco-sa-asaftd-sslvpndma-dos-HRrqB9Yx)");
script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch");
script_set_attribute(attribute:"description", value:
"A vulnerability in the SSL VPN negotiation process for Cisco Adaptive Security Appliance (ASA) Software could allow an
unauthenticated, remote attacker to cause a reload of an affected device, resulting in a denial of service (DoS)
condition. The vulnerability is due to inefficient direct memory access (DMA) memory management during the negotiation
phase of an SSL VPN connection. An attacker could exploit this vulnerability by sending a steady stream of crafted
Datagram TLS (DTLS) traffic to an affected device. A successful exploit could allow the attacker to exhaust DMA memory
on the device and cause a DoS condition.
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
# https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-sslvpndma-dos-HRrqB9Yx
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?24a25658");
script_set_attribute(attribute:"see_also", value:"https://tools.cisco.com/security/center/viewErp.x?alertId=ERP-74302");
script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvu59817");
script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID CSCvu59817");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
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-2020-3529");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_cwe_id(400);
script_set_attribute(attribute:"vuln_publication_date", value:"2020/10/21");
script_set_attribute(attribute:"patch_publication_date", value:"2020/10/21");
script_set_attribute(attribute:"plugin_publication_date", value:"2022/12/16");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/a:cisco:firepower_threat_defense");
script_set_attribute(attribute:"stig_severity", value:"I");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"CISCO");
script_copyright(english:"This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/Cisco/ASA/model");
exit(0);
}
include('ccf.inc');
include('cisco_workarounds.inc');
var product_info = cisco::get_product_info(name:'Cisco Adaptive Security Appliance (ASA) Software');
var model = product_info['model'];
// Cisco Firepower 1000, 2100, 4100, 9000 Series
// Cisco ASA 5500-X Series Firewalls
// Cisco Adaptive Security Virtual Appliance (ASAv)
// Cisco 3000 Series Industrial Security Appliances (ISA)
if (model !~ "(FPR-?|Firepower)\s*(1[0-9]{3}|1K|21[0-9]{2}|2K|41[0-9]{2}|4K|9[0-9]{3}|9K)"
&& model !~ "ASA55[0-9]{2}-X" && toupper(model) >!< 'ASAV' && model !~ "ISA3[0-9]{3}")
{
// CVRF has entries for "Cisco ASA Service Module" and we have no detection for it by itself,
// i.e. not coupled with a device/model string e.g. Cisco ASA Services Module for Cisco Catalyst 6500 Series Switches
if (report_paranoia < 2)
audit(AUDIT_PARANOID);
else
audit(AUDIT_DEVICE_NOT_VULN, 'The remote host');
}
var vuln_ranges = [
{'min_ver': '0.0', 'fix_ver': '9.6.4.45'},
{'min_ver': '9.7.0', 'fix_ver': '9.8.4.29'},
{'min_ver': '9.9.0', 'fix_ver': '9.9.2.80'},
{'min_ver': '9.10.0', 'fix_ver': '9.10.1.44'},
{'min_ver': '9.11.0', 'fix_ver': '9.12.4.4'},
{'min_ver': '9.13.0', 'fix_ver': '9.13.1.13'},
{'min_ver': '9.14.0', 'fix_ver': '9.14.1.30'}
];
var workarounds = make_list(CISCO_WORKAROUNDS['generic_workaround']);
var workaround_params = WORKAROUND_CONFIG['ssl_vpn'];
var reporting = make_array(
'port' , 0,
'severity' , SECURITY_WARNING,
'version' , product_info['version'],
'cmds' , make_list('show running-config'),
'bug_id' , 'CSCvu59817'
);
cisco::check_and_report(
product_info:product_info,
workarounds:workarounds,
workaround_params:workaround_params,
reporting:reporting,
vuln_ranges:vuln_ranges
);
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
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
52.6%