Debian DLA-2835-1 : rsyslog - 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-2835. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

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

if (description)
{
  script_id(155738);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/12/01");

  script_cve_id("CVE-2019-17041", "CVE-2019-17042");

  script_name(english:"Debian DLA-2835-1 : rsyslog - 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-2835 advisory.

  - An issue was discovered in Rsyslog v8.1908.0. contrib/pmaixforwardedfrom/pmaixforwardedfrom.c has a heap
    overflow in the parser for AIX log messages. The parser tries to locate a log message delimiter (in this
    case, a space or a colon) but fails to account for strings that do not satisfy this constraint. If the
    string does not match, then the variable lenMsg will reach the value zero and will skip the sanity check
    that detects invalid log messages. The message will then be considered valid, and the parser will eat up
    the nonexistent colon delimiter. In doing so, it will decrement lenMsg, a signed integer, whose value was
    zero and now becomes minus one. The following step in the parser is to shift left the contents of the
    message. To do this, it will call memmove with the right pointers to the target and destination strings,
    but the lenMsg will now be interpreted as a huge value, causing a heap overflow. (CVE-2019-17041)

  - An issue was discovered in Rsyslog v8.1908.0. contrib/pmcisconames/pmcisconames.c has a heap overflow in
    the parser for Cisco log messages. The parser tries to locate a log message delimiter (in this case, a
    space or a colon), but fails to account for strings that do not satisfy this constraint. If the string
    does not match, then the variable lenMsg will reach the value zero and will skip the sanity check that
    detects invalid log messages. The message will then be considered valid, and the parser will eat up the
    nonexistent colon delimiter. In doing so, it will decrement lenMsg, a signed integer, whose value was zero
    and now becomes minus one. The following step in the parser is to shift left the contents of the message.
    To do this, it will call memmove with the right pointers to the target and destination strings, but the
    lenMsg will now be interpreted as a huge value, causing a heap overflow. (CVE-2019-17042)

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=942065");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/source-package/rsyslog");
  script_set_attribute(attribute:"see_also", value:"https://www.debian.org/lts/security/2021/dla-2835");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2019-17041");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2019-17042");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/stretch/rsyslog");
  script_set_attribute(attribute:"solution", value:
"Upgrade the rsyslog packages.

For Debian 9 stretch, these problems have been fixed in version 8.24.0-1+deb9u1.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/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:L/PR:N/UI:N/S:U/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-2019-17042");

  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:"2019/10/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/11/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/12/01");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:rsyslog");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:rsyslog-czmq");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:rsyslog-elasticsearch");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:rsyslog-gnutls");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:rsyslog-gssapi");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:rsyslog-hiredis");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:rsyslog-kafka");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:rsyslog-mongodb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:rsyslog-mysql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:rsyslog-pgsql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:rsyslog-relp");
  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': 'rsyslog', 'reference': '8.24.0-1+deb9u1'},
    {'release': '9.0', 'prefix': 'rsyslog-czmq', 'reference': '8.24.0-1+deb9u1'},
    {'release': '9.0', 'prefix': 'rsyslog-elasticsearch', 'reference': '8.24.0-1+deb9u1'},
    {'release': '9.0', 'prefix': 'rsyslog-gnutls', 'reference': '8.24.0-1+deb9u1'},
    {'release': '9.0', 'prefix': 'rsyslog-gssapi', 'reference': '8.24.0-1+deb9u1'},
    {'release': '9.0', 'prefix': 'rsyslog-hiredis', 'reference': '8.24.0-1+deb9u1'},
    {'release': '9.0', 'prefix': 'rsyslog-kafka', 'reference': '8.24.0-1+deb9u1'},
    {'release': '9.0', 'prefix': 'rsyslog-mongodb', 'reference': '8.24.0-1+deb9u1'},
    {'release': '9.0', 'prefix': 'rsyslog-mysql', 'reference': '8.24.0-1+deb9u1'},
    {'release': '9.0', 'prefix': 'rsyslog-pgsql', 'reference': '8.24.0-1+deb9u1'},
    {'release': '9.0', 'prefix': 'rsyslog-relp', 'reference': '8.24.0-1+deb9u1'}
];

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_HOLE,
    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, 'rsyslog / rsyslog-czmq / rsyslog-elasticsearch / rsyslog-gnutls / etc');
}