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:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS
Percentile
48.3%
According to its self-reported version, Cisco ASR 5000 Series Software is affected by a denial-of-service vulnerability. An unauthenticated, remote attacker can exploit this, via a series of specially crafted packets, to prevent the interface from receiving traffic.
Please see the included Cisco BIDs and Cisco Security Advisory for more information.
#
# (C) Tenable Network Security, Inc.
#
include("compat.inc");
if (description)
{
script_id(126340);
script_version("1.3");
script_set_attribute(attribute:"plugin_modification_date", value:"2020/08/07");
script_cve_id("CVE-2019-1869");
script_bugtraq_id(108853);
script_xref(name:"CISCO-BUG-ID", value:"CSCvn06757");
script_xref(name:"CISCO-SA", value:"cisco-sa-20190619-staros-asr-dos");
script_xref(name:"IAVA", value:"2019-A-0214-S");
script_name(english:"Cisco StarOS Denial of Service Vulnerability");
script_summary(english:"Checks the version of Cisco ASR 5000 Series Software");
script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
script_set_attribute(attribute:"description", value:
"According to its self-reported version, Cisco ASR 5000 Series Software
is affected by a denial-of-service vulnerability. An unauthenticated,
remote attacker can exploit this, via a series of specially crafted
packets, to prevent the interface from receiving traffic.
Please see the included Cisco BIDs and Cisco Security Advisory for more
information.");
# https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190619-staros-asr-dos
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?80b9b550");
script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvn06757");
script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID CSCvn06757");
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-2019-1869");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_cwe_id(824);
script_set_attribute(attribute:"vuln_publication_date", value:"2019/06/19");
script_set_attribute(attribute:"patch_publication_date", value:"2019/06/19");
script_set_attribute(attribute:"plugin_publication_date", value:"2019/06/28");
script_set_attribute(attribute:"potential_vulnerability", value:"true");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:asr_5000_series");
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) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/Cisco/ASR/Model", "Host/Cisco/StarOS", "Settings/ParanoidReport");
exit(0);
}
include("audit.inc");
include("cisco_func.inc");
include("cisco_kb_cmd_func.inc");
get_kb_item_or_exit("Host/Cisco/StarOS");
version = get_kb_item_or_exit("Host/Cisco/StarOS/Version");
model = get_kb_item_or_exit("Host/Cisco/ASR/Model");
major = NULL;
build = NULL;
fix = NULL;
train = NULL;
# only affects ASR 5000 series systems
if (model !~ "^50\d{2}$")
audit(AUDIT_DEVICE_NOT_VULN, 'The ASR ' + model);
# Normalize train characters
version= toupper(version);
# For newer versions, We may be able to get the build number during detection
build = get_kb_item("Host/Cisco/StarOS/Build");
if (!empty_or_null(build))
version += "." + build;
# defensive check for the pregmatches below
if (version !~ "^[\d\.]+\([\d\.]+" &&
version !~ "^[\d\.]+([A-Z]{1,2}\d+)?\.\d+$")
audit(AUDIT_VER_FORMAT, version);
# only two feature sets are vulnerable
if (report_paranoia < 2) audit(AUDIT_PARANOID);
# old style of versioning 15.0(5439), style change mid 16.1, making
# all of the old style versions fall into the vulnerable range.
if ("(" >< version)
{
major = pregmatch(pattern:"^([\d\.]+)\(", string:version);
if(!isnull(major))
{
major = major[1];
if (isnull(build))
{
build = pregmatch(pattern:"^[\d\.]+\(([\d\.]+)", string:version);
if(!isnull(build))
{
build = build[1];
# Set the train to an empty string, or it causes issues when
# seeing if a patched version exists using NULL as the value
train = '';
}
else
exit(1, "Unable to extract build number.");
}
}
else
exit(1, "Unable to extract version number.");
}
else
{
# extract major, train, and build for new style
extract = pregmatch(pattern:"^([\d\.]+)\.([A-Z]{1,2}\d+)?\.?(\d+)?", string:version);
if (!isnull(extract))
{
major = extract[1];
train = extract[2];
if (isnull(build))
build = extract[3];
}
}
# Defensive checking for versions that we haven't yet seen
if(empty_or_null(major) || empty_or_null(build))
exit(1, "An error occurred during version extraction.");
fix_array = make_array(
"21.6", { B16: 70802 },
"21.12", { CN0: 70901, M0: 70847, RG0:70868 },
"21.13", { A0: 70850 }
);
maj_checks = [
{maj:'21.6.13', build:70803},
{maj:'21.7.11', build:70813},
{maj:'21.8.10', build:70835},
{maj:'21.9.7', build:70905},
{maj:'21.10.2', build:70893},
{maj:'21.11.1', build:70889},
{maj:'21.12.0', build:71155}
];
foreach check (maj_checks)
{
if (major == check.maj && int(build) < check.build)
{
fix = check.maj + '.' + check.build;
break;
}
}
if (empty_or_null(fix) &&
!empty_or_null(fix_array[major]) &&
!empty_or_null(train) &&
int(build) < fix_array[major][train])
fix = major + "." + train + "." + fix_array[major][train];
if (fix)
{
security_report_cisco(
port : 0,
severity : SECURITY_WARNING,
version : version,
fix : fix,
bug_id : 'CSCvn06757'
);
}
else audit(AUDIT_DEVICE_NOT_VULN, "ASR " + model, version);
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:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS
Percentile
48.3%