CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
87.3%
The remote Ubuntu 18.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-5200-1 advisory.
It was discovered that the urllib.request.AbstractBasicAuthHandler class
in Python contains regex allowing for catastrophic backtracking. Specially
crafted traffic from a malicious HTTP server could cause a regular expression
denial of service (ReDoS) condition for a client. (CVE-2020-8492)
It was discovered that the urllib.request.AbstractBasicAuthHandler class
in Python contains regex with a quadratic worst-case time complexity.
Specially crafted traffic from a malicious HTTP server could cause a regular
expression denial of service (ReDoS) condition for a client. (CVE-2021-3733)
It was discovered that the Python urllib http client could enter into an infinite
loop when incorrectly handling certain server responses (100 Continue response).
Specially crafted traffic from a malicious HTTP server could cause a denial of
service (DoS) condition for a client. (CVE-2021-3737)
Tenable has extracted the preceding description block directly from the Ubuntu security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-5200-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(156171);
script_version("1.8");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");
script_cve_id("CVE-2020-8492", "CVE-2021-3733", "CVE-2021-3737");
script_xref(name:"USN", value:"5200-1");
script_xref(name:"IAVA", value:"2020-A-0103-S");
script_xref(name:"IAVA", value:"2021-A-0497-S");
script_name(english:"Ubuntu 18.04 LTS : Python vulnerabilities (USN-5200-1)");
script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
script_set_attribute(attribute:"description", value:
"The remote Ubuntu 18.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in
the USN-5200-1 advisory.
It was discovered that the urllib.request.AbstractBasicAuthHandler class
in Python contains regex allowing for catastrophic backtracking. Specially
crafted traffic from a malicious HTTP server could cause a regular expression
denial of service (ReDoS) condition for a client. (CVE-2020-8492)
It was discovered that the urllib.request.AbstractBasicAuthHandler class
in Python contains regex with a quadratic worst-case time complexity.
Specially crafted traffic from a malicious HTTP server could cause a regular
expression denial of service (ReDoS) condition for a client. (CVE-2021-3733)
It was discovered that the Python urllib http client could enter into an infinite
loop when incorrectly handling certain server responses (100 Continue response).
Specially crafted traffic from a malicious HTTP server could cause a denial of
service (DoS) condition for a client. (CVE-2021-3737)
Tenable has extracted the preceding description block directly from the Ubuntu security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/notices/USN-5200-1");
script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:C");
script_set_cvss_temporal_vector("CVSS2#E:POC/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:P/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-3737");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2020/01/30");
script_set_attribute(attribute:"patch_publication_date", value:"2021/12/17");
script_set_attribute(attribute:"plugin_publication_date", value:"2021/12/18");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:idle-python3.7");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:idle-python3.8");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpython3.7");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpython3.7-dev");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpython3.7-minimal");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpython3.7-stdlib");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpython3.7-testsuite");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpython3.8");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpython3.8-dev");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpython3.8-minimal");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpython3.8-stdlib");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpython3.8-testsuite");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3.7");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3.7-dev");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3.7-examples");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3.7-minimal");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3.7-venv");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3.8");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3.8-dev");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3.8-examples");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3.8-minimal");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3.8-venv");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_set_attribute(attribute:"stig_severity", value:"I");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Ubuntu Local Security Checks");
script_copyright(english:"Ubuntu Security Notice (C) 2021-2024 Canonical, Inc. / NASL script (C) 2021-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");
exit(0);
}
include('debian_package.inc');
if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('18.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 18.04', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) audit(AUDIT_PACKAGE_LIST_MISSING);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Ubuntu', cpu);
var pkgs = [
{'osver': '18.04', 'pkgname': 'idle-python3.7', 'pkgver': '3.7.5-2ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'idle-python3.8', 'pkgver': '3.8.0-3ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'libpython3.7', 'pkgver': '3.7.5-2ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'libpython3.7-dev', 'pkgver': '3.7.5-2ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'libpython3.7-minimal', 'pkgver': '3.7.5-2ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'libpython3.7-stdlib', 'pkgver': '3.7.5-2ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'libpython3.7-testsuite', 'pkgver': '3.7.5-2ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'libpython3.8', 'pkgver': '3.8.0-3ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'libpython3.8-dev', 'pkgver': '3.8.0-3ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'libpython3.8-minimal', 'pkgver': '3.8.0-3ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'libpython3.8-stdlib', 'pkgver': '3.8.0-3ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'libpython3.8-testsuite', 'pkgver': '3.8.0-3ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'python3.7', 'pkgver': '3.7.5-2ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'python3.7-dev', 'pkgver': '3.7.5-2ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'python3.7-examples', 'pkgver': '3.7.5-2ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'python3.7-minimal', 'pkgver': '3.7.5-2ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'python3.7-venv', 'pkgver': '3.7.5-2ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'python3.8', 'pkgver': '3.8.0-3ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'python3.8-dev', 'pkgver': '3.8.0-3ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'python3.8-examples', 'pkgver': '3.8.0-3ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'python3.8-minimal', 'pkgver': '3.8.0-3ubuntu1~18.04.2'},
{'osver': '18.04', 'pkgname': 'python3.8-venv', 'pkgver': '3.8.0-3ubuntu1~18.04.2'}
];
var flag = 0;
foreach var package_array ( pkgs ) {
var osver = NULL;
var pkgname = NULL;
var pkgver = NULL;
if (!empty_or_null(package_array['osver'])) osver = package_array['osver'];
if (!empty_or_null(package_array['pkgname'])) pkgname = package_array['pkgname'];
if (!empty_or_null(package_array['pkgver'])) pkgver = package_array['pkgver'];
if (osver && pkgname && pkgver) {
if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) flag++;
}
}
if (flag)
{
var extra = '';
extra += ubuntu_report_get();
security_report_v4(
port : 0,
severity : SECURITY_HOLE,
extra : extra
);
exit(0);
}
else
{
var tested = ubuntu_pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'idle-python3.7 / idle-python3.8 / libpython3.7 / libpython3.7-dev / etc');
}
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
87.3%