CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:L/Au:N/C:P/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
AI Score
Confidence
High
EPSS
Percentile
56.7%
coturn is prone to a loopback bypass vulnerability.
# Copyright (C) 2021 Greenbone Networks GmbH
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-or-later
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
CPE = "cpe:/a:coturn:coturn";
if (description)
{
script_oid("1.3.6.1.4.1.25623.1.0.145204");
script_version("2021-08-17T09:01:01+0000");
script_tag(name:"last_modification", value:"2021-08-17 09:01:01 +0000 (Tue, 17 Aug 2021)");
script_tag(name:"creation_date", value:"2021-01-20 09:47:13 +0000 (Wed, 20 Jan 2021)");
script_tag(name:"cvss_base", value:"6.4");
script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:P/A:N");
script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N");
script_tag(name:"severity_origin", value:"NVD");
script_tag(name:"severity_date", value:"2021-01-20 03:15:00 +0000 (Wed, 20 Jan 2021)");
script_cve_id("CVE-2020-26262");
script_tag(name:"qod_type", value:"remote_banner_unreliable");
script_tag(name:"solution_type", value:"VendorFix");
script_name("coturn < 4.5.2 Loopback Bypass Vulnerability");
script_category(ACT_GATHER_INFO);
script_copyright("Copyright (C) 2021 Greenbone Networks GmbH");
script_family("General");
script_dependencies("gb_coturn_http_detect.nasl");
script_mandatory_keys("coturn/detected");
script_tag(name:"summary", value:"coturn is prone to a loopback bypass vulnerability.");
script_tag(name:"vuldetect", value:"Checks if a vulnerable version is present on the target host.");
script_tag(name:"insight", value:"By default coturn does not allow peers to connect and relay packets to
loopback addresses in the range of 127.x.x.x. However, it was observed that when sending a CONNECT request
with the XOR-PEER-ADDRESS value of 0.0.0.0, a successful response was received and subsequently,
CONNECTIONBIND also received a successful response. Coturn then is able to relay packets to the loopback
interface.
Additionally, when coturn is listening on IPv6, which is default, the loopback interface can also be reached
by making use of either [::1] or [::] as the peer address.");
script_tag(name:"impact", value:"By using the address 0.0.0.0 as the peer address, a malicious user will be
able to relay packets to the loopback interface, unless --denied-peer-ip=0.0.0.0 (or similar) has been
specified. Since the default configuration implies that loopback peers are not allowed, coturn
administrators may choose to not set the denied-peer-ip setting.");
script_tag(name:"affected", value:"coturn prior to version 4.5.2.");
script_tag(name:"solution", value:"Update to version 4.5.2 or later.");
script_xref(name:"URL", value:"https://github.com/coturn/coturn/security/advisories/GHSA-6g6j-r9rf-cm7p");
script_xref(name:"URL", value:"https://www.rtcsec.com/post/2021/01/details-about-cve-2020-26262-bypass-of-coturns-default-access-control-protection");
exit(0);
}
include("host_details.inc");
include("version_func.inc");
if (!version = get_app_version(cpe: CPE, nofork: TRUE))
exit(0);
if (version_is_less(version: version, test_version: "4.5.2")) {
report = report_fixed_ver(installed_version: version, fixed_version: "4.5.2");
security_message(port: 0, data: report);
exit(0);
}
exit(99);
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:L/Au:N/C:P/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
AI Score
Confidence
High
EPSS
Percentile
56.7%