Vulnerabilities > CVE-1999-0103

#
# This script was written by Mathieu Perrin <[email protected]>
#
# See the Nessus Scripts License for details
#

# Changes by Tenable:
# - Revised plugin title (9/17/09)
# - Changed family (10/8/09)
# - Changed CVSS score/risk factor (09/24/19)


include("compat.inc");

if(description)
{
 script_id(10198);
 script_version ("1.29");
 script_cvs_date("Date: 2019/10/04 16:48:26");

 script_cve_id("CVE-1999-0103");

 script_name(english:"Quote of the Day (QOTD) Service Detection");

 script_set_attribute(attribute:"synopsis", value:
"The quote service (qotd) is running on this host." );
 script_set_attribute(attribute:"description", value:
"A server listens for TCP connections on TCP port 17. Once a connection 
is established a short message is sent out the connection (and any 
data received is thrown away). The service closes the connection 
after sending the quote.

Another quote of the day service is defined as a datagram based
application on UDP.  A server listens for UDP datagrams on UDP port 17.
When a datagram is received, an answering datagram is sent containing 
a quote (the data in the received datagram is ignored).

An easy attack is 'pingpong' which IP spoofs a packet between two machines
running qotd. This will cause them to spew characters at each other,
slowing the machines down and saturating the network." );
 script_set_attribute(attribute:"solution", value:
"- Under Unix systems, comment out the 'qotd' line in /etc/inetd.conf
  and restart the inetd process
 
- Under Windows systems, set the following registry keys to 0 :
  HKLM\System\CurrentControlSet\Services\SimpTCP\Parameters\EnableTcpQotd
  HKLM\System\CurrentControlSet\Services\SimpTCP\Parameters\EnableUdpQotd
   
Then launch cmd.exe and type :

   net stop simptcp
   net start simptcp
   
To restart the service." );
 script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
 script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H");
 script_set_attribute(attribute:"cvss_score_source", value:"CVE-1999-0103");

 script_set_attribute(attribute:"plugin_publication_date", value: "1999/11/30");
 script_set_attribute(attribute:"vuln_publication_date", value: "1996/02/08");
 script_set_attribute(attribute:"plugin_type", value:"remote");
 script_end_attributes();

 script_summary(english:"Checks for the presence of qotd");
 script_category(ACT_GATHER_INFO);
 script_copyright(english:"This script is Copyright (C) 1999-2019 Mathieu Perrin");
 script_family(english:"Service detection");
 script_dependencie("find_service1.nasl", "find_service2.nasl");
 exit(0);
}
 
#
# The script code starts here
#
include("global_settings.inc");
include("misc_func.inc");

if(get_udp_port_state(17))
{		  
 udpsoc = open_sock_udp(17);
 if ( ! udpsoc ) exit(0);
 send(socket:udpsoc, data:'\r\n');
 b = recv(socket:udpsoc, length:1024);
 if(b)
 {
  b = chomp(b);
  if (report_verbosity > 1 && strlen(b) > 0)
   security_warning(port:17, protocol: "udp", extra: '\nThe service sent :\n\n', b, '\n');
  else
   security_warning(port:17, protocol:"udp");
  register_service(port:17, ipproto:"udp", proto:"qotd");
 }
 close(udpsoc);
}

if(get_port_state(17))
{
 p = known_service(port:17);	# May fork
 if(!p || p == "qotd")
 {
 soc = open_sock_tcp(17);
 if(soc)
  {
    a = recv_line(socket:soc, length:1024);
    if(a)
    {
      a = chomp(a);
      if (report_verbosity > 1 && strlen(a) > 0)
        security_warning(port:17, extra: '\nThe service sent :\n\n', a, '\n');
      else
        security_warning(17);
      if (!p) register_service(port:17, ipproto:"tcp", proto:"qotd");
    }
    close(soc);
  }
 }
}

#
# This script was written by Mathieu Perrin <[email protected]>
#
# See the Nessus Scripts License for details
#

# Changes by Tenable:
# - Revised plugin title, family change (9/17/09)
# - Minor description touch-ups (9/14/10)

include("compat.inc");

if(description)
{
 script_id(10043);
 script_version ("1.40");
 script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/12");

 script_cve_id("CVE-1999-0103");

 script_name(english:"Chargen UDP Service Remote DoS");

 script_set_attribute(attribute:"synopsis", value:
"The remote host is running a 'chargen' service." );
 script_set_attribute(attribute:"description", value:
"When contacted, chargen responds with some random characters (something
like all the characters in the alphabet in a row). When contacted via UDP, it
will respond with a single UDP packet. When contacted via TCP, it will
continue spewing characters until the client closes the connection.

The purpose of this service was to mostly test the TCP/IP protocol
by itself, to make sure that all the packets were arriving at their
destination unaltered. It is unused these days, so it is suggested
you disable it, as an attacker may use it to set up an attack against
this host, or against a third-party host using this host as a relay.

An easy attack is 'ping-pong' in which an attacker spoofs a packet between
two machines running chargen. This will cause them to spew characters at
each other, slowing the machines down and saturating the network." );
 script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?f0dbdf05" );
 script_set_attribute(attribute:"solution", value:
"- Under Unix systems, comment out the 'chargen' line in /etc/inetd.conf
  and restart the inetd process

- Under Windows systems, set the following registry keys to 0 :
  HKLM\System\CurrentControlSet\Services\SimpTCP\Parameters\EnableTcpChargen
  HKLM\System\CurrentControlSet\Services\SimpTCP\Parameters\EnableUdpChargen

 Then launch cmd.exe and type :

   net stop simptcp
   net start simptcp

To restart the service." );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'Chargen Probe Utility');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");
script_set_attribute(attribute:"plugin_publication_date", value: "1999/11/29");
 script_set_attribute(attribute:"vuln_publication_date", value: "1996/02/08");
script_set_attribute(attribute:"plugin_type", value:"remote");
script_end_attributes();

 script_summary(english:"Checks for the presence of chargen");
 script_category(ACT_GATHER_INFO);
 script_copyright(english:"This script is Copyright (C) 1999-2020 Mathieu Perrin");
 script_family(english:"Denial of Service");
 script_dependencie("find_service1.nasl");

 exit(0);
}

#
# The script code starts here
#

include("misc_func.inc");


if(get_udp_port_state(19))
{		  
 udpsoc = open_sock_udp(19);
 if ( ! udpsoc ) exit(0);
 data = string("\r\n");
 send(socket:udpsoc, data:data);
 b = recv(socket:udpsoc, length:1024);
 if(strlen(b) > 255)security_warning(port:19,protocol:"udp");
 
 close(udpsoc);
}

if(get_port_state(19))
{
 p = known_service(port:19);	# May fork
 if(!p || p == "chargen")
 {
 soc = open_sock_tcp(19);
 if(soc)
  {
    a = recv(socket:soc, length:255, min:255);
    if(strlen(a) > 255)security_warning(19);
    close(soc);
  }
 }
}