dnsmasq < 2.73rc4 setup_reply() Function Return Value Checking Information Disclosure

#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(87596);
  script_version("1.4");
  script_cvs_date("Date: 2019/11/20");

  script_cve_id("CVE-2015-3294");
  script_bugtraq_id(74452);

  script_name(english:"dnsmasq < 2.73rc4 setup_reply() Function Return Value Checking Information Disclosure");
  script_summary(english:"Checks the version of dnsmasq.");

  script_set_attribute(attribute:"synopsis", value:
"The remote DNS / DHCP service is affected by an information disclosure
vulnerability.");
  script_set_attribute(attribute:"description", value:
"The remote dnsmasq server is running a version prior to 2.73rc4. It
is, therefore, affected by an information disclosure vulnerability due
not properly checking the return value from the setup_reply() function
during TCP connections. An unauthenticated, remote attacker can
exploit this to disclose sensitive information.");
  # http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commitdiff;h=ad4a8ff7d9097008d7623df8543df435bfddeac8
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?3c7d3afa");
  script_set_attribute(attribute:"see_also", value:"http://www.thekelleys.org.uk/dnsmasq/CHANGELOG");
  script_set_attribute(attribute:"solution", value:
"Upgrade to dnsmasq 2.73rc4 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2015-3294");

  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:"2015/04/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2015/04/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/12/22");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:thekelleys:dnsmasq");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"DNS");

  script_copyright(english:"This script is Copyright (C) 2015-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("dns_version.nasl");
  script_require_keys("dns_server/version", "Settings/ParanoidReport");
  script_require_ports("Services/dns", 53);

  exit(0);
}

include("audit.inc");
include("misc_func.inc");
include("global_settings.inc");

app_name = "dnsmasq";

port = get_kb_item("Services/udp/dns");
if (!port) port = 53;

if (report_paranoia < 2) audit(AUDIT_PARANOID);

version = get_kb_item_or_exit("dns_server/version");
version = tolower(version);

if (version !~ "dnsmasq-(v)?")
	audit(AUDIT_NOT_LISTEN, app_name, port);

if (version =~ "^dnsmasq-(v)?([0-9\.][01]+|[0-2]\.)([0-7]|[0-7][0-2]|[0-6][0-9]|[0-6][0-9](test[0-9][0-9]|rc[0-6])|[0-7][0-3](test[0-6]|rc[0-3]))$")
{
  if (report_verbosity > 0)
  {
    report =
      '\n  Installed version : ' + version +
      '\n  Fixed version     : dnsmasq-2.73rc4' +
      '\n';

    security_warning(port:port, proto:"udp", extra:report);
  }
  else security_warning(port:port, proto:"udp");
}
else audit(AUDIT_INST_VER_NOT_VULN, app_name, version);