Amazon Linux AMI : glibc (ALAS-2018-1109)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2018-1109.
#

include("compat.inc");

if (description)
{
  script_id(119468);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/05/31");

  script_cve_id("CVE-2017-16997", "CVE-2018-11236", "CVE-2018-11237", "CVE-2018-6485");
  script_xref(name:"ALAS", value:"2018-1109");

  script_name(english:"Amazon Linux AMI : glibc (ALAS-2018-1109)");
  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:
"A buffer overflow has been discovered in the GNU C Library (aka glibc
or libc6) in the __mempcpy_avx512_no_vzeroupper function when
particular conditions are met. An attacker could use this
vulnerability to cause a denial of service or potentially execute
code.(CVE-2018-11237)

elf/dl-load.c in the GNU C Library (aka glibc or libc6) 2.19 through
2.26 mishandles RPATH and RUNPATH containing $ORIGIN for a privileged
(setuid or AT_SECURE) program, which allows local users to gain
privileges via a Trojan horse library in the current working
directory, related to the fillin_rpath and decompose_rpath functions.
This is associated with misinterpretion of an empty RPATH/RUNPATH
token as the './' directory. NOTE: this configuration of RPATH/RUNPATH
for a privileged program is apparently very uncommon; most likely, no
such program is shipped with any common Linux
distribution.(CVE-2017-16997)

stdlib/canonicalize.c in the GNU C Library (aka glibc or libc6) 2.27
and earlier, when processing very long pathname arguments to the
realpath function, could encounter an integer overflow on 32-bit
architectures, leading to a stack-based buffer overflow and,
potentially, arbitrary code execution.(CVE-2018-11236)

An integer overflow in the implementation of the posix_memalign in
memalign functions in the GNU C Library (aka glibc or libc6) 2.26 and
earlier could cause these functions to return a pointer to a heap area
that is too small, potentially leading to heap
corruption.(CVE-2018-6485)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/ALAS-2018-1109.html"
  );
  script_set_attribute(
    attribute:"solution",
    value:"Run 'yum update glibc' 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:"cvss_score_source", value:"CVE-2017-16997");
  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:glibc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:glibc-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:glibc-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:glibc-debuginfo-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:glibc-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:glibc-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:glibc-static");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:glibc-utils");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nscd");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/12/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/12/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/12/07");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2018-2022 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:"glibc-2.17-260.175.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"glibc-common-2.17-260.175.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"glibc-debuginfo-2.17-260.175.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"glibc-debuginfo-common-2.17-260.175.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"glibc-devel-2.17-260.175.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"glibc-headers-2.17-260.175.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"glibc-static-2.17-260.175.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"glibc-utils-2.17-260.175.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"nscd-2.17-260.175.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, "glibc / glibc-common / glibc-debuginfo / glibc-debuginfo-common / etc");
}