Sybase SQL sa Account Blank Password

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

# This script is based on mssql_blank_password.nasl which is (C) H D Moore

include('compat.inc');

if (description)
{
  script_id(17162);
  script_version("1.11");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/05/05");

  script_name(english:"Sybase SQL sa Account Blank Password");

  script_set_attribute(attribute:"synopsis", value:
"The remote database service has an account with a blank password.");
  script_set_attribute(attribute:"description", value:
"The remote Sybase SQL server has the default 'sa' account enabled
without any password. 

An attacker may use this flaw to execute commands against the remote
host as well as read database content.");
  script_set_attribute(attribute:"solution", value:
"Either disable this account or set a password for it.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_attribute(attribute:"cvss_score_source", value:"manual");
  script_set_attribute(attribute:"cvss_score_rationale", value:"score from an analysis done by Tenable");

  script_set_attribute(attribute:"plugin_publication_date", value:"2005/02/21");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:sybase:adaptive_server_enterprise");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:sybase:adaptive_server");
  script_set_attribute(attribute:"thorough_tests", value:"true");
  script_end_attributes();

  script_category(ACT_ATTACK);
  script_family(english:"Databases");

  script_copyright(english:"This script is Copyright (C) 2005-2023 Tenable Network Security, Inc.");

  script_dependencies("sybase_detect.nasl");
  script_exclude_keys("global_settings/supplied_logins_only");
  script_require_ports("Services/sybase", 5000);

  exit(0);
}

#
# The script code starts here
#

var pkt_hdr = raw_string(
    0x02, 0x00, 0x02, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
);


var pkt_pt2 = raw_string (
    0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x61, 0x30, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x20, 0x18, 0x81, 0xb8, 0x2c, 0x08, 0x03,
    0x01, 0x06, 0x0a, 0x09, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x73, 0x71, 0x75, 0x65, 0x6c, 0x64, 0x61,
    0x20, 0x31, 0x2e, 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x0b, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00
);

var pkt_pt3 = raw_string (
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x04, 0x02, 0x00, 0x00, 0x4d, 0x53, 0x44,
    0x42, 0x4c, 0x49, 0x42, 0x00, 0x00, 0x00, 0x07, 0x06, 0x00, 0x00,
    0x00, 0x00, 0x0d, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00
);

var pkt_lang = raw_string(
    0x02, 0x01, 0x00, 0x47, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 0x30, 0x30, 0x00, 0x00,
    0x00, 0x03, 0x00, 0x00, 0x00
);

function make_sql_login_pkt (username, password)
{
    local_var nul, pblen, pbuf, plen, ppad, sql_packet, ublen, ubuf, ulen, upad;

    ulen = strlen(username);
    plen = strlen(password);
    
    upad = 30 - ulen;
    ppad = 30 - plen;
    
    ubuf = "";
    pbuf = "";
    
    nul = raw_string(0x00);
    
    if(ulen)
    {
        ublen = raw_string(ulen % 255);
    } else {
        ublen = raw_string(0x00);
    }
    
    if(plen)
    {
        pblen = raw_string(plen % 255);
    } else {
        pblen = raw_string(0x00);
    }  

    ubuf = username + crap(data:nul, length:upad);
    pbuf = password + crap(data:nul, length:ppad);

    sql_packet = pkt_hdr + ubuf + ublen + pbuf + pblen + pkt_pt2 + pblen + pbuf + pkt_pt3;
    
    # returning this as a string is NOT working!
    return sql_packet;
}


var port = get_kb_item("Services/sybase");
if(!port)port = 5000;

var found = 0;

if(get_port_state(port))
{
    var soc = open_sock_tcp(port);

    if(soc)
    {
        # this creates a variable called sql_packet
        var sql_packet = make_sql_login_pkt(username:"sa", password:"");

        send(socket:soc, data:sql_packet);
        send(socket:soc, data:pkt_lang);

	    var r  = recv(socket:soc, length:255);
	    close(soc);

	    if(strlen(r) > 10 &&
	       ord(r[8]) == 0xE3)
	    {
	    var version = substr(r, strlen(r) - 13, strlen(r) - 10 );
	    var strver = NULL;
        var i;
	    for ( i = 0 ; i < 4 ; i ++ )
		{
		 if ( strver) strver += '.';
		 strver += ord(version[i]);
		 }
	    set_kb_item(name:"sybase/version", value:strver);
            security_hole(port);
	    }
    }
}