Python is prone to a Regular Expresson Denial of Service (ReDoS) vulnerability.
# Copyright (C) 2020 Greenbone Networks GmbH
#
# 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.
if(description)
{
script_oid("1.3.6.1.4.1.25623.1.0.113637");
script_version("2020-03-10T07:36:36+0000");
script_tag(name:"last_modification", value:"2020-03-10 07:36:36 +0000 (Tue, 10 Mar 2020)");
script_tag(name:"creation_date", value:"2020-02-17 14:07:49 +0000 (Mon, 17 Feb 2020)");
script_tag(name:"cvss_base", value:"7.1");
script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:N/C:N/I:N/A:C");
script_tag(name:"qod_type", value:"executable_version_unreliable");
script_tag(name:"solution_type", value:"NoneAvailable");
script_cve_id("CVE-2020-8492");
script_name("Python 2.7.x <= 2.7.17, 3.5 <= 3.5.9, 3.6.x <= 3.6.10, 3.7.x <= 3.7.6, 3.8.x <= 3.8.1 Regular Expression Denial of Service (ReDoS) Vulnerability (Linux)");
script_category(ACT_GATHER_INFO);
script_copyright("Copyright (C) 2020 Greenbone Networks GmbH");
script_family("Denial of Service");
script_dependencies("gb_python_detect_lin.nasl");
script_mandatory_keys("python/linux/detected");
script_tag(name:"summary", value:"Python is prone to a Regular Expresson Denial of Service (ReDoS) vulnerability.");
script_tag(name:"vuldetect", value:"Checks if a vulnerable version is present on the target host.");
script_tag(name:"insight", value:"The AbstractBasicAuthHandler class of the urllib.request module uses an inefficient regular expression (catastrophic backtracking)
which can be exploited by an attacker to cause a denial of service.");
script_tag(name:"impact", value:"Successful exploitation would allow an attacker to crash the application.");
script_tag(name:"affected", value:"Python 2.7 through 2.7.17, 3.5 through 3.5.9, 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1");
script_tag(name:"solution", value:"No known solution is available as of 17th February, 2020. Information regarding this issue will be updated once solution details are available.");
script_xref(name:"URL", value:"https://bugs.python.org/issue39503");
script_xref(name:"URL", value:"https://python-security.readthedocs.io/vuln/urllib-basic-auth-Nregex.html");
exit(0);
}
CPE = "cpe:/a:python:python";
include( "host_details.inc" );
include( "version_func.inc" );
if( ! infos = get_app_version_and_location( cpe: CPE, exit_no_version: TRUE ) ) exit( 0 );
version = infos["version"];
location = infos["location"];
if( version_in_range( version: version, test_version: "2.7.0", test_version2: "2.7.17" ) ) {
report = report_fixed_ver( installed_version: version, fixed_version: "None", install_path: location );
security_message( data: report, port: 0 );
exit( 0 );
}
if( version_in_range( version: version, test_version: "3.5.0", test_version2: "3.5.9" ) ) {
report = report_fixed_ver( installed_version: version, fixed_version: "None", install_path: location );
security_message( data: report, port: 0 );
exit( 0 );
}
if( version_in_range( version: version, test_version: "3.6.0", test_version2: "3.6.10" ) ) {
report = report_fixed_ver( installed_version: version, fixed_version: "None", install_path: location );
security_message( data: report, port: 0 );
exit( 0 );
}
if( version_in_range( version: version, test_version: "3.7.0", test_version2: "3.7.6" ) ) {
report = report_fixed_ver( installed_version: version, fixed_version: "None", install_path: location );
security_message( data: report, port: 0 );
exit( 0 );
}
if( version_in_range( version: version, test_version: "3.8.0", test_version2: "3.8.1" ) ) {
report = report_fixed_ver( installed_version: version, fixed_version: "None", install_path: location );
security_message( data: report, port: 0 );
exit( 0 );
}
exit( 99 );