The upstream patch for CVE-2014-8080 introduced checks against the REXML.entity_expansion_text_limit, but did not add restrictions to limit the number of expansions performed, i.e. checks against the REXML::Document.entity_expansion_limit. As a consequence, even with the patch applied, a small XML document could cause REXML to use an excessive amount of CPU time. High memory usage can be achieved using larger inputs.
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2014-448.
#
include("compat.inc");
if (description)
{
script_id(79297);
script_version("1.6");
script_cvs_date("Date: 2018/04/18 15:09:35");
script_cve_id("CVE-2014-8090");
script_xref(name:"ALAS", value:"2014-448");
script_name(english:"Amazon Linux AMI : ruby20 (ALAS-2014-448)");
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:
"The upstream patch for CVE-2014-8080 introduced checks against the
REXML.entity_expansion_text_limit, but did not add restrictions to
limit the number of expansions performed, i.e. checks against the
REXML::Document.entity_expansion_limit. As a consequence, even with
the patch applied, a small XML document could cause REXML to use an
excessive amount of CPU time. High memory usage can be achieved using
larger inputs."
);
script_set_attribute(
attribute:"see_also",
value:"https://alas.aws.amazon.com/ALAS-2014-448.html"
);
script_set_attribute(
attribute:"solution",
value:"Run 'yum update ruby20' to update your system."
);
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/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:ruby20");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby20-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby20-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby20-doc");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby20-irb");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby20-libs");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem20-bigdecimal");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem20-io-console");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem20-psych");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygems20");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygems20-devel");
script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");
script_set_attribute(attribute:"patch_publication_date", value:"2014/11/13");
script_set_attribute(attribute:"plugin_publication_date", value:"2014/11/18");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2014-2018 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:"ruby20-2.0.0.598-1.20.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"ruby20-debuginfo-2.0.0.598-1.20.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"ruby20-devel-2.0.0.598-1.20.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"ruby20-doc-2.0.0.598-1.20.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"ruby20-irb-2.0.0.598-1.20.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"ruby20-libs-2.0.0.598-1.20.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygem20-bigdecimal-1.2.0-1.20.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygem20-io-console-0.4.2-1.20.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygem20-psych-2.0.0-1.20.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygems20-2.0.14-1.20.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygems20-devel-2.0.14-1.20.amzn1")) 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, "ruby20 / ruby20-debuginfo / ruby20-devel / ruby20-doc / ruby20-irb / etc");
}