CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:C/I:C/A:C
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
AI Score
Confidence
Low
EPSS
Percentile
99.2%
The remote Ubuntu 18.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-4294-1 advisory.
It was discovered that OpenSMTPD mishandled certain input. A remote, unauthenticated attacker could use this vulnerability to execute arbitrary shell commands as any non-root user. (CVE-2020-8794)
It was discovered that OpenSMTPD did not properly handle hardlinks under certain conditions. An unprivileged local attacker could read the first line of any file on the filesystem. (CVE-2020-8793)
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.
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4294-1. The text
# itself is copyright (C) Canonical, Inc. See
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
#
include('compat.inc');
if (description)
{
script_id(134299);
script_version("1.6");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");
script_cve_id("CVE-2020-8793", "CVE-2020-8794");
script_xref(name:"USN", value:"4294-1");
script_name(english:"Ubuntu 18.04 LTS : OpenSMTPD vulnerabilities (USN-4294-1)");
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 a package installed that is affected by multiple vulnerabilities as referenced in
the USN-4294-1 advisory.
It was discovered that OpenSMTPD mishandled certain input. A remote, unauthenticated attacker could use
this vulnerability to execute arbitrary shell commands as any non-root user. (CVE-2020-8794)
It was discovered that OpenSMTPD did not properly handle hardlinks under certain conditions. An
unprivileged local attacker could read the first line of any file on the filesystem. (CVE-2020-8793)
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-4294-1");
script_set_attribute(attribute:"solution", value:
"Update the affected opensmtpd package.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-8794");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"metasploit_name", value:'OpenSMTPD OOB Read Local Privilege Escalation');
script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2020/02/25");
script_set_attribute(attribute:"patch_publication_date", value:"2020/03/02");
script_set_attribute(attribute:"plugin_publication_date", value:"2020/03/06");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:opensmtpd");
script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Ubuntu Local Security Checks");
script_copyright(english:"Ubuntu Security Notice (C) 2020-2024 Canonical, Inc. / NASL script (C) 2020-2024 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': 'opensmtpd', 'pkgver': '6.0.3p1-1ubuntu0.2'}
];
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, 'opensmtpd');
}
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:C/I:C/A:C
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
AI Score
Confidence
Low
EPSS
Percentile
99.2%