OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c.(CVE-2018-15473)
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALAS-2018-1075.
#
include("compat.inc");
if (description)
{
script_id(117708);
script_version("1.4");
script_cvs_date("Date: 2019/04/05 23:25:05");
script_cve_id("CVE-2018-15473");
script_xref(name:"ALAS", value:"2018-1075");
script_name(english:"Amazon Linux 2 : openssh (ALAS-2018-1075)");
script_summary(english:"Checks rpm output for the updated packages");
script_set_attribute(
attribute:"synopsis",
value:"The remote Amazon Linux 2 host is missing a security update."
);
script_set_attribute(
attribute:"description",
value:
"OpenSSH through 7.7 is prone to a user enumeration vulnerability due
to not delaying bailout for an invalid authenticating user until after
the packet containing the request has been fully parsed, related to
auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c.(CVE-2018-15473)"
);
script_set_attribute(
attribute:"see_also",
value:"https://alas.aws.amazon.com/AL2/ALAS-2018-1075.html"
);
script_set_attribute(
attribute:"solution",
value:"Run 'yum update openssh' to update your system."
);
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
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:L/I:N/A:N");
script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"exploit_framework_canvas", value:"true");
script_set_attribute(attribute:"canvas_package", value:'CANVAS');
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-askpass");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-cavs");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-clients");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-keycat");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-ldap");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-server");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openssh-server-sysvinit");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:pam_ssh_agent_auth");
script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
script_set_attribute(attribute:"patch_publication_date", value:"2018/09/25");
script_set_attribute(attribute:"plugin_publication_date", value:"2018/09/27");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_family(english:"Amazon Linux Local Security Checks");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");
exit(0);
}
include("audit.inc");
include("global_settings.inc");
include("rpm.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/AmazonLinux/release");
if (isnull(release) || !strlen(release)) audit(AUDIT_OS_NOT, "Amazon Linux");
os_ver = pregmatch(pattern: "^AL(A|\d)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "2")
{
if (os_ver == 'A') os_ver = 'AMI';
audit(AUDIT_OS_NOT, "Amazon Linux 2", "Amazon Linux " + os_ver);
}
if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
flag = 0;
if (rpm_check(release:"AL2", reference:"openssh-7.4p1-16.amzn2.0.5")) flag++;
if (rpm_check(release:"AL2", reference:"openssh-askpass-7.4p1-16.amzn2.0.5")) flag++;
if (rpm_check(release:"AL2", reference:"openssh-cavs-7.4p1-16.amzn2.0.5")) flag++;
if (rpm_check(release:"AL2", reference:"openssh-clients-7.4p1-16.amzn2.0.5")) flag++;
if (rpm_check(release:"AL2", reference:"openssh-debuginfo-7.4p1-16.amzn2.0.5")) flag++;
if (rpm_check(release:"AL2", reference:"openssh-keycat-7.4p1-16.amzn2.0.5")) flag++;
if (rpm_check(release:"AL2", reference:"openssh-ldap-7.4p1-16.amzn2.0.5")) flag++;
if (rpm_check(release:"AL2", reference:"openssh-server-7.4p1-16.amzn2.0.5")) flag++;
if (rpm_check(release:"AL2", reference:"openssh-server-sysvinit-7.4p1-16.amzn2.0.5")) flag++;
if (rpm_check(release:"AL2", reference:"pam_ssh_agent_auth-0.10.3-2.16.amzn2.0.5")) flag++;
if (flag)
{
if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
else security_warning(0);
exit(0);
}
else
{
tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "openssh / openssh-askpass / openssh-cavs / openssh-clients / etc");
}
Vendor | Product | Version | CPE |
---|---|---|---|
amazon | linux | openssh | p-cpe:/a:amazon:linux:openssh |
amazon | linux | openssh-askpass | p-cpe:/a:amazon:linux:openssh-askpass |
amazon | linux | openssh-cavs | p-cpe:/a:amazon:linux:openssh-cavs |
amazon | linux | openssh-clients | p-cpe:/a:amazon:linux:openssh-clients |
amazon | linux | openssh-debuginfo | p-cpe:/a:amazon:linux:openssh-debuginfo |
amazon | linux | openssh-keycat | p-cpe:/a:amazon:linux:openssh-keycat |
amazon | linux | openssh-ldap | p-cpe:/a:amazon:linux:openssh-ldap |
amazon | linux | openssh-server | p-cpe:/a:amazon:linux:openssh-server |
amazon | linux | openssh-server-sysvinit | p-cpe:/a:amazon:linux:openssh-server-sysvinit |
amazon | linux | pam_ssh_agent_auth | p-cpe:/a:amazon:linux:pam_ssh_agent_auth |