WU-FTPD S/KEY Authentication ftpd.c skey_challenge Function Remote Overflow

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

include("compat.inc");

if (description)
{
 script_id(14372);
 script_version("1.20");

 script_cve_id("CVE-2004-0185");
 script_bugtraq_id(8893);
 script_xref(name:"DSA", value:"DSA-457-1");
 script_xref(name:"RHSA", value:"2004:096-09");
 
 script_name(english:"WU-FTPD S/KEY Authentication ftpd.c skey_challenge Function Remote Overflow");
 
 script_set_attribute(attribute:"synopsis", value:
"The remote FTP server seems to be vulnerable to a remote buffer overflow." );
 script_set_attribute(attribute:"description", value:
"This version of WU-FTPD contains a remote overflow if s/key support is enabled. 
The skey_challenge function fails to perform bounds checking on the 
name variable resulting in a buffer overflow. 
With a specially crafted request, an attacker can execute arbitrary 
code resulting in a loss of integrity and/or availability.

It appears that this vulnerability may be exploited prior to authentication.
It is reported that S/Key support is not enabled by default, 
though some operating system distributions which ship WU-FTPD may have it 
enabled.

*** Nessus solely relied on the banner of the remote server
*** to issue this warning, so it may be a false positive." );
 script_set_attribute(attribute:"see_also", value:"http://www.securiteam.com/unixfocus/6X00Q1P8KC.html" );
 script_set_attribute(attribute:"solution", value:
"Upgrade to WU-FTPD 2.6.3 when available or disable SKEY or apply the
patches available at http://www.wu-ftpd.org" );
 script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
 script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
 script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
 script_set_attribute(attribute:"exploit_available", value:"false");
		
 script_set_attribute(attribute:"plugin_publication_date", value: "2004/08/25");
 script_set_attribute(attribute:"vuln_publication_date", value: "2000/06/07");
 script_cvs_date("Date: 2018/08/07 16:46:50");
script_set_attribute(attribute:"potential_vulnerability", value:"true");
script_set_attribute(attribute:"plugin_type", value:"remote");
script_end_attributes();

		    
 
 script_summary(english:"Checks the banner of the remote wu-ftpd server");
 script_category(ACT_GATHER_INFO);
 script_family(english:"FTP");
 
 script_copyright(english:"This script is Copyright (C) 2004-2018 Tenable Network Security, Inc.");
		  
 script_dependencie("ftpserver_detect_type_nd_version.nasl", "ftp_anonymous.nasl");
 script_require_keys("ftp/login", "ftp/wuftpd", "Settings/ParanoidReport");
 script_require_ports("Services/ftp", 21);
  
 exit(0);
}

#
# The script code starts here : 
#
include("ftp_func.inc");
include("backport.inc");
include("global_settings.inc");
include("audit.inc");

if (report_paranoia < 2) audit(AUDIT_PARANOID);

port = get_ftp_port(default: 21);


banner = get_backport_banner(banner:get_ftp_banner(port: port));
if (! banner ) exit(0);

if(egrep(pattern:".*(wu|wuftpd)-(2\.(5\.|6\.[012])).*", string:banner))
	security_hole(port);