Amazon Linux AMI : libpng (ALAS-2015-615)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2015-615.
#

include("compat.inc");

if (description)
{
  script_id(87341);
  script_version("2.4");
  script_cvs_date("Date: 2018/04/18 15:09:35");

  script_cve_id("CVE-2015-7981", "CVE-2015-8472");
  script_xref(name:"ALAS", value:"2015-615");

  script_name(english:"Amazon Linux AMI : libpng (ALAS-2015-615)");
  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:
"It was discovered that the png_get_PLTE() and png_set_PLTE() functions
of libpng did not correctly calculate the maximum palette sizes for
bit depths of less than 8. In case an application tried to use these
functions in combination with properly calculated palette sizes, this
could lead to a buffer overflow or out-of-bounds reads. An attacker
could exploit this to cause a crash or potentially execute arbitrary
code by tricking an unsuspecting user into processing a specially
crafted PNG image. However, the exact impact is dependent on the
application using the library. (CVE-2015-7981)

An array-indexing error was discovered in the png_convert_to_rfc1123()
function of libpng. An attacker could possibly use this flaw to cause
an out-of-bounds read by tricking an unsuspecting user into processing
a specially crafted PNG image. (CVE-2015-8472)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/ALAS-2015-615.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Run 'yum update libpng' 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:L/I:L/A:L");

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

  script_set_attribute(attribute:"patch_publication_date", value:"2015/12/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/12/15");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2015-2018 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:"libpng-1.2.49-2.14.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"libpng-debuginfo-1.2.49-2.14.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"libpng-devel-1.2.49-2.14.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"libpng-static-1.2.49-2.14.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, "libpng / libpng-debuginfo / libpng-devel / libpng-static");
}