Amazon Linux 2 : ruby (ALAS-2018-983)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALAS-2018-983.
#

include("compat.inc");

if (description)
{
  script_id(109136);
  script_version("1.2");
  script_cvs_date("Date: 2019/07/10 16:04:12");

  script_cve_id("CVE-2017-17790", "CVE-2018-1000073", "CVE-2018-1000074", "CVE-2018-1000075", "CVE-2018-1000076", "CVE-2018-1000077", "CVE-2018-1000078", "CVE-2018-1000079");
  script_xref(name:"ALAS", value:"2018-983");

  script_name(english:"Amazon Linux 2 : ruby (ALAS-2018-983)");
  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:
"Path traversal when writing to a symlinked basedir outside of the root

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series:
2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5
series: 2.5.0 and earlier, prior to trunk revision 62422 contains a
Directory Traversal vulnerability in install_location function of
package.rb that can result in path traversal when writing to a
symlinked basedir outside of the root. This vulnerability appears to
have been fixed in 2.7.6. (CVE-2018-1000073)

Improper verification of signatures in tarball allows to install
mis-signed gem :

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series:
2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5
series: 2.5.0 and earlier, prior to trunk revision 62422 contains a
Improper Verification of Cryptographic Signature vulnerability in
package.rb that can result in a mis-signed gem could be installed, as
the tarball would contain multiple gem signatures.. This vulnerability
appears to have been fixed in 2.7.6. (CVE-2018-1000076)

Infinite loop vulnerability due to negative size in tar header causes
Denial of Service

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series:
2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5
series: 2.5.0 and earlier, prior to trunk revision 62422 contains a
infinite loop caused by negative size vulnerability in ruby gem
package tar header that can result in a negative size could cause an
infinite loop.. This vulnerability appears to have been fixed in
2.7.6. (CVE-2018-1000075)

Command injection in lib/resolv.rb:lazy_initialize() allows arbitrary
code execution :

The 'lazy_initialize' function in lib/resolv.rb did not properly
process certain filenames. A remote attacker could possibly exploit
this flaw to inject and execute arbitrary commands. (CVE-2017-17790)

Missing URL validation on spec home attribute allows malicious gem to
set an invalid homepage URL :

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series:
2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5
series: 2.5.0 and earlier, prior to trunk revision 62422 contains a
Improper Input Validation vulnerability in ruby gems specification
homepage attribute that can result in a malicious gem could set an
invalid homepage URL. This vulnerability appears to have been fixed in
2.7.6. (CVE-2018-1000077)

XSS vulnerability in homepage attribute when displayed via gem server

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series:
2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5
series: 2.5.0 and earlier, prior to trunk revision 62422 contains a
Cross Site Scripting (XSS) vulnerability in gem server display of
homepage attribute that can result in XSS. This attack appear to be
exploitable via the victim must browse to a malicious gem on a
vulnerable gem server. This vulnerability appears to have been fixed
in 2.7.6. (CVE-2018-1000078)

Unsafe Object Deserialization Vulnerability in gem owner allowing
arbitrary code execution on specially crafted YAML

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series:
2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5
series: 2.5.0 and earlier, prior to trunk revision 62422 contains a
Deserialization of Untrusted Data vulnerability in owner command that
can result in code execution. This attack appear to be exploitable via
victim must run the `gem owner` command on a gem with a specially
crafted YAML file. This vulnerability appears to have been fixed in
2.7.6. (CVE-2018-1000074)

Path traversal issue during gem installation allows to write to
arbitrary filesystem locations

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series:
2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5
series: 2.5.0 and earlier, prior to trunk revision 62422 contains a
Directory Traversal vulnerability in gem installation that can result
in the gem could write to arbitrary filesystem locations during
installation. This attack appear to be exploitable via the victim must
install a malicious gem. This vulnerability appears to have been fixed
in 2.7.6. (CVE-2018-1000079)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/AL2/ALAS-2018-983.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Run 'yum update ruby' to update your system."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  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_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby-irb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ruby-tcltk");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem-bigdecimal");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem-io-console");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem-json");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem-minitest");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem-psych");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem-rake");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygem-rdoc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygems");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:rubygems-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/12/20");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/04/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/04/18");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  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", cpu:"x86_64", reference:"ruby-2.0.0.648-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", cpu:"x86_64", reference:"ruby-debuginfo-2.0.0.648-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", cpu:"x86_64", reference:"ruby-devel-2.0.0.648-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", reference:"ruby-doc-2.0.0.648-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", reference:"ruby-irb-2.0.0.648-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", cpu:"x86_64", reference:"ruby-libs-2.0.0.648-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", cpu:"x86_64", reference:"ruby-tcltk-2.0.0.648-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", cpu:"x86_64", reference:"rubygem-bigdecimal-1.2.0-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", cpu:"x86_64", reference:"rubygem-io-console-0.4.2-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", cpu:"x86_64", reference:"rubygem-json-1.7.7-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", reference:"rubygem-minitest-4.3.2-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", cpu:"x86_64", reference:"rubygem-psych-2.0.0-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", reference:"rubygem-rake-0.9.6-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", reference:"rubygem-rdoc-4.0.0-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", reference:"rubygems-2.0.14.1-33.amzn2.0.1")) flag++;
if (rpm_check(release:"AL2", reference:"rubygems-devel-2.0.14.1-33.amzn2.0.1")) 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, "ruby / ruby-debuginfo / ruby-devel / ruby-doc / ruby-irb / etc");
}