9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.9 High
AI Score
Confidence
High
7.5 High
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
0.086 Low
EPSS
Percentile
94.4%
OpenSSL is prone to a buffer overflow 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:openssl:openssl";
if(description)
{
script_oid("1.3.6.1.4.1.25623.1.0.112980");
script_version("2021-09-06T09:01:34+0000");
script_tag(name:"last_modification", value:"2021-09-06 09:01:34 +0000 (Mon, 06 Sep 2021)");
script_tag(name:"creation_date", value:"2021-08-25 07:05:11 +0000 (Wed, 25 Aug 2021)");
script_tag(name:"cvss_base", value:"7.5");
script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:P/A:P");
script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
script_tag(name:"severity_origin", value:"NVD");
script_tag(name:"severity_date", value:"2021-08-31 16:37:00 +0000 (Tue, 31 Aug 2021)");
script_cve_id("CVE-2021-3711");
script_tag(name:"qod_type", value:"remote_banner_unreliable");
script_tag(name:"solution_type", value:"VendorFix");
script_name("OpenSSL: SM2 Decryption Buffer Overflow (20210824) - Linux");
script_category(ACT_GATHER_INFO);
script_copyright("Copyright (C) 2021 Greenbone Networks GmbH");
script_family("General");
script_dependencies("gb_openssl_consolidation.nasl", "os_detection.nasl");
script_mandatory_keys("openssl/detected", "Host/runs_unixoide");
script_tag(name:"summary", value:"OpenSSL is prone to a buffer overflow vulnerability.");
script_tag(name:"vuldetect", value:"Checks if a vulnerable version is present on the target host.");
script_tag(name:"insight", value:"In order to decrypt SM2 encrypted data an application is
expected to call the API function EVP_PKEY_decrypt(). Typically an application will call this
function twice. The first time, on entry, the 'out' parameter can be NULL and,
on exit, the 'outlen' parameter is populated with the buffer size required to
hold the decrypted plaintext. The application can then allocate a sufficiently
sized buffer and call EVP_PKEY_decrypt() again, but this time passing a non-NULL
value for the 'out' parameter.
A bug in the implementation of the SM2 decryption code means that the
calculation of the buffer size required to hold the plaintext returned by the
first call to EVP_PKEY_decrypt() can be smaller than the actual size required by
the second call. This can lead to a buffer overflow when EVP_PKEY_decrypt() is
called by the application a second time with a buffer that is too small.");
script_tag(name:"impact", value:"A malicious attacker who is able present SM2 content for
decryption to an application could cause attacker chosen data to overflow the buffer by up to a
maximum of 62 bytes altering the contents of other data held after the
buffer, possibly changing application behaviour or causing the application to
crash. The location of the buffer is application dependent but is typically
heap allocated.");
script_tag(name:"affected", value:"OpenSSL 1.1.1 through 1.1.1k.");
script_tag(name:"solution", value:"Update to version 1.1.1l or later.");
script_xref(name:"URL", value:"https://www.openssl.org/news/secadv/20210824.txt");
exit(0);
}
include("host_details.inc");
include("version_func.inc");
if (isnull(port = get_app_port(cpe: CPE)))
exit(0);
if (!infos = get_app_version_and_location(cpe: CPE, port: port, exit_no_version: TRUE))
exit(0);
version = infos["version"];
location = infos["location"];
if (version_in_range(version: version, test_version: "1.1.1", test_version2: "1.1.1k")) {
report = report_fixed_ver(installed_version: version, fixed_version: "1.1.1l", install_path: location);
security_message(port: port, data: report);
exit(0);
}
exit(99);
9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.9 High
AI Score
Confidence
High
7.5 High
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
0.086 Low
EPSS
Percentile
94.4%