Debian DLA-2753-1 : qemu - LTS security update

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dla-2753. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(152982);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/09/03");

  script_cve_id(
    "CVE-2021-3527",
    "CVE-2021-3592",
    "CVE-2021-3594",
    "CVE-2021-3595",
    "CVE-2021-3682",
    "CVE-2021-3713"
  );

  script_name(english:"Debian DLA-2753-1 : qemu - LTS security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing one or more security-related updates.");
  script_set_attribute(attribute:"description", value:
"The remote Debian 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the
dla-2753 advisory.

  - A flaw was found in the USB redirector device (usb-redir) of QEMU. Small USB packets are combined into a
    single, large transfer request, to reduce the overhead and improve performance. The combined size of the
    bulk transfer is used to dynamically allocate a variable length array (VLA) on the stack without proper
    validation. Since the total size is not bounded, a malicious guest could use this flaw to influence the
    array length and cause the QEMU process to perform an excessive allocation on the stack, resulting in a
    denial of service. (CVE-2021-3527)

  - An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw
    exists in the bootp_input() function and could occur while processing a udp packet that is smaller than
    the size of the 'bootp_t' structure. A malicious guest could use this flaw to leak 10 bytes of
    uninitialized heap memory from the host. The highest threat from this vulnerability is to data
    confidentiality. This flaw affects libslirp versions prior to 4.6.0. (CVE-2021-3592)

  - An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw
    exists in the udp_input() function and could occur while processing a udp packet that is smaller than the
    size of the 'udphdr' structure. This issue may lead to out-of-bounds read access or indirect host memory
    disclosure to the guest. The highest threat from this vulnerability is to data confidentiality. This flaw
    affects libslirp versions prior to 4.6.0. (CVE-2021-3594)

  - An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw
    exists in the tftp_input() function and could occur while processing a udp packet that is smaller than the
    size of the 'tftp_t' structure. This issue may lead to out-of-bounds read access or indirect host memory
    disclosure to the guest. The highest threat from this vulnerability is to data confidentiality. This flaw
    affects libslirp versions prior to 4.6.0. (CVE-2021-3595)

  - A flaw was found in the USB redirector device emulation of QEMU in versions prior to 6.1.0-rc2. It occurs
    when dropping packets during a bulk transfer from a SPICE client due to the packet queue being full. A
    malicious SPICE client could use this flaw to make QEMU call free() with faked heap chunk metadata,
    resulting in a crash of QEMU or potential code execution with the privileges of the QEMU process on the
    host. (CVE-2021-3682)

  - An out-of-bounds write flaw was found in the UAS (USB Attached SCSI) device emulation of QEMU in versions
    prior to 6.2.0-rc0. The device uses the guest supplied stream number unchecked, which can lead to out-of-
    bounds access to the UASDevice->data3 and UASDevice->status3 fields. A malicious guest user could use this
    flaw to crash QEMU or potentially achieve code execution with the privileges of the QEMU process on the
    host. (CVE-2021-3713)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=988157");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/source-package/qemu");
  script_set_attribute(attribute:"see_also", value:"https://www.debian.org/lts/security/2021/dla-2753");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-3527");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-3592");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-3594");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-3595");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-3682");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-3713");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/stretch/qemu");
  script_set_attribute(attribute:"solution", value:
"Upgrade the qemu packages.

For Debian 9 stretch, these problems have been fixed in version 1");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:S/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-3682");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/05/26");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/09/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/09/03");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-block-extra");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-guest-agent");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-kvm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-system");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-system-arm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-system-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-system-mips");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-system-misc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-system-ppc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-system-sparc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-system-x86");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-user");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-user-binfmt");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-user-static");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:qemu-utils");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Debian Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2021 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");

  exit(0);
}

include('audit.inc');
include('debian_package.inc');

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);

var release = get_kb_item('Host/Debian/release');
if ( isnull(release) ) audit(AUDIT_OS_NOT, 'Debian');
var release = chomp(release);
if (! preg(pattern:"^(9)\.[0-9]+", string:release)) audit(AUDIT_OS_NOT, 'Debian 9.0', 'Debian ' + release);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Debian', cpu);

var pkgs = [
    {'release': '9.0', 'prefix': 'qemu', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-block-extra', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-guest-agent', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-kvm', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-system', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-system-arm', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-system-common', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-system-mips', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-system-misc', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-system-ppc', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-system-sparc', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-system-x86', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-user', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-user-binfmt', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-user-static', 'reference': '1:2.8+dfsg-6+deb9u15'},
    {'release': '9.0', 'prefix': 'qemu-utils', 'reference': '1:2.8+dfsg-6+deb9u15'}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var release = NULL;
  var prefix = NULL;
  var reference = NULL;
  if (!empty_or_null(package_array['release'])) release = package_array['release'];
  if (!empty_or_null(package_array['prefix'])) prefix = package_array['prefix'];
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (release && prefix && reference) {
    if (deb_check(release:release, prefix:prefix, reference:reference)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : deb_report_get()
  );
  exit(0);
}
else
{
  var tested = deb_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'qemu / qemu-block-extra / qemu-guest-agent / qemu-kvm / qemu-system / etc');
}