Amazon Linux AMI : gnupg2 (ALAS-2013-237)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2013-237.
#

include("compat.inc");

if (description)
{
  script_id(70899);
  script_version("1.4");
  script_cvs_date("Date: 2018/04/18 15:09:35");

  script_cve_id("CVE-2013-4351", "CVE-2013-4402");
  script_xref(name:"ALAS", value:"2013-237");

  script_name(english:"Amazon Linux AMI : gnupg2 (ALAS-2013-237)");
  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:
"GnuPG 1.4.x, 2.0.x, and 2.1.x treats a key flags subpacket with all
bits cleared (no usage permitted) as if it has all bits set (all usage
permitted), which might allow remote attackers to bypass intended
cryptographic protection mechanisms by leveraging the subkey.

The compressed packet parser in GnuPG 1.4.x before 1.4.15 and 2.0.x
before 2.0.22 allows remote attackers to cause a denial of service
(infinite recursion) via a crafted OpenPGP message."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/ALAS-2013-237.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Run 'yum update gnupg2' to update your system."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:N");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:gnupg2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:gnupg2-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:gnupg2-smime");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");

  script_set_attribute(attribute:"patch_publication_date", value:"2013/10/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2013/11/14");
  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:"gnupg2-2.0.22-1.24.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"gnupg2-debuginfo-2.0.22-1.24.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"gnupg2-smime-2.0.22-1.24.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, "gnupg2 / gnupg2-debuginfo / gnupg2-smime");
}