A denial of service flaw was found in the OpenSSH GSSAPI authentication implementation. A remote, authenticated user could use this flaw to make the OpenSSH server daemon (sshd) use an excessive amount of memory, leading to a denial of service. GSSAPI authentication is enabled by default (‘GSSAPIAuthentication yes’ in ‘/etc/ssh/sshd_config’). (CVE-2011-5000)
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2012-99.
#
include("compat.inc");
if (description)
{
script_id(69706);
script_version("1.5");
script_cvs_date("Date: 2018/04/18 15:09:34");
script_cve_id("CVE-2011-5000");
script_xref(name:"ALAS", value:"2012-99");
script_xref(name:"RHSA", value:"2012:0884");
script_name(english:"Amazon Linux AMI : openssh (ALAS-2012-99)");
script_summary(english:"Checks rpm output for the updated packages");
script_set_attribute(
attribute:"synopsis",
value:"The remote Amazon Linux AMI host is missing a security update."
);
script_set_attribute(
attribute:"description",
value:
"A denial of service flaw was found in the OpenSSH GSSAPI
authentication implementation. A remote, authenticated user could use
this flaw to make the OpenSSH server daemon (sshd) use an excessive
amount of memory, leading to a denial of service. GSSAPI
authentication is enabled by default ('GSSAPIAuthentication yes' in
'/etc/ssh/sshd_config'). (CVE-2011-5000)"
);
script_set_attribute(
attribute:"see_also",
value:"https://alas.aws.amazon.com/ALAS-2012-99.html"
);
script_set_attribute(
attribute:"solution",
value:"Run 'yum update openssh' to update your system."
);
script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:S/C:N/I:N/A:P");
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-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-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:pam_ssh_agent_auth");
script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");
script_set_attribute(attribute:"patch_publication_date", value:"2012/07/05");
script_set_attribute(attribute:"plugin_publication_date", value:"2013/09/04");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2013-2018 Tenable Network Security, Inc.");
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 != "A")
{
if (os_ver == 'A') os_ver = 'AMI';
audit(AUDIT_OS_NOT, "Amazon Linux AMI", "Amazon Linux " + os_ver);
}
if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
flag = 0;
if (rpm_check(release:"ALA", reference:"openssh-5.3p1-81.17.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"openssh-clients-5.3p1-81.17.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"openssh-debuginfo-5.3p1-81.17.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"openssh-ldap-5.3p1-81.17.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"openssh-server-5.3p1-81.17.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"pam_ssh_agent_auth-0.9-81.17.amzn1")) flag++;
if (flag)
{
if (report_verbosity > 0) security_note(port:0, extra:rpm_report_get());
else security_note(0);
exit(0);
}
else
{
tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "openssh / openssh-clients / openssh-debuginfo / openssh-ldap / etc");
}
Vendor | Product | Version | CPE |
---|---|---|---|
amazon | linux | openssh | p-cpe:/a:amazon:linux:openssh |
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-ldap | p-cpe:/a:amazon:linux:openssh-ldap |
amazon | linux | openssh-server | p-cpe:/a:amazon:linux:openssh-server |
amazon | linux | pam_ssh_agent_auth | p-cpe:/a:amazon:linux:pam_ssh_agent_auth |
amazon | linux | cpe:/o:amazon:linux |