Amazon Linux AMI : ruby24 (ALAS-2017-915)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2017-915.
#

include("compat.inc");

if (description)
{
  script_id(104181);
  script_version("3.5");
  script_cvs_date("Date: 2019/04/10 16:10:16");

  script_cve_id("CVE-2017-0898", "CVE-2017-0899", "CVE-2017-0900", "CVE-2017-0901", "CVE-2017-0902", "CVE-2017-0903", "CVE-2017-10784", "CVE-2017-14033", "CVE-2017-14064");
  script_xref(name:"ALAS", value:"2017-915");

  script_name(english:"Amazon Linux AMI : ruby24 (ALAS-2017-915)");
  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:
"Arbitrary heap exposure during a JSON.generate call

Ruby through 2.2.7, 2.3.x through 2.3.4, and 2.4.x through 2.4.1 can
expose arbitrary memory during a JSON.generate call. The issues lies
in using strdup in ext/json/ext/generator/generator.c, which will stop
after encountering a '\\0' byte, returning a pointer to a string of
length zero, which is not the length stored in space_len.
(CVE-2017-14064)

Escape sequence injection vulnerability in the Basic authentication of
WEBrick

The Basic authentication code in WEBrick library in Ruby before 2.2.8,
2.3.x before 2.3.5, and 2.4.x through 2.4.1 allows remote attackers to
inject terminal emulator escape sequences into its log and possibly
execute arbitrary commands via a crafted user name. (CVE-2017-10784)

Buffer underrun in OpenSSL ASN1 decode

The decode method in the OpenSSL::ASN1 module in Ruby before 2.2.8,
2.3.x before 2.3.5, and 2.4.x through 2.4.1 allows attackers to cause
a denial of service (interpreter crash) via a crafted string.
(CVE-2017-14033)

No size limit in summary length of gem spec

RubyGems version 2.6.12 and earlier is vulnerable to maliciously
crafted gem specifications to cause a denial of service attack against
RubyGems clients who have issued a `query` command. (CVE-2017-0900)

Arbitrary file overwrite due to incorrect validation of specification
name

RubyGems version 2.6.12 and earlier fails to validate specification
names, allowing a maliciously crafted gem to potentially overwrite any
file on the filesystem. (CVE-2017-0901)

DNS hijacking vulnerability

RubyGems version 2.6.12 and earlier is vulnerable to a DNS hijacking
vulnerability that allows a MITM attacker to force the RubyGems client
to download and install gems from a server that the attacker controls.
(CVE-2017-0902)

Buffer underrun vulnerability in Kernel.sprintf

Ruby before 2.4.2, 2.3.5, and 2.2.8 is vulnerable to a malicious
format string which contains a precious specifier (*) with a huge
minus value. Such situation can lead to a buffer overrun, resulting in
a heap memory corruption or an information disclosure from the heap.
(CVE-2017-0898)

Escape sequence in the 'summary' field of gemspec

RubyGems version 2.6.12 and earlier is vulnerable to maliciously
crafted gem specifications that include terminal escape characters.
Printing the gem specification would execute terminal escape
sequences. (CVE-2017-0899)

A vulnerability was found where the rubygems module was vulnerable to
an unsafe YAML deserialization when inspecting a gem. Applications
inspecting gem files without installing them can be tricked to execute
arbitrary code in the context of the ruby interpreter. (CVE-2017-0903)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/ALAS-2017-915.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Run 'yum update ruby24' to update your system."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/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:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/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:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby24");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby24-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby24-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby24-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby24-irb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby24-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem24-bigdecimal");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem24-did_you_mean");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem24-io-console");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem24-json");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem24-psych");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem24-xmlrpc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygems24");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygems24-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");

  script_set_attribute(attribute:"patch_publication_date", value:"2017/10/26");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/10/27");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2019 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 != "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:"ruby24-2.4.2-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"ruby24-debuginfo-2.4.2-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"ruby24-devel-2.4.2-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"ruby24-doc-2.4.2-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"ruby24-irb-2.4.2-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"ruby24-libs-2.4.2-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygem24-bigdecimal-1.3.0-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygem24-did_you_mean-1.1.0-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygem24-io-console-0.4.6-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygem24-json-2.0.4-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygem24-psych-2.2.2-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygem24-xmlrpc-0.2.1-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygems24-2.6.13-1.30.4.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"rubygems24-devel-2.6.13-1.30.4.amzn1")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:rpm_report_get());
  else security_hole(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "ruby24 / ruby24-debuginfo / ruby24-devel / ruby24-doc / ruby24-irb / etc");
}