简单搞个ftp的demo，secpod_ftp_anonymous.nasl 以这个例子举例
环境
openvas-nasl 20.8.0 openvas 20.8.0 gvm-libs 20.8.0
调试脚本secpod_ftp_anonymous.nasl，用于确认用户名密码
###############################################################################
# OpenVAS Vulnerability Test
# Anonymous FTP Login Detection
# Authors:
# Antu Sanadi <santu@secpod.com>
# Copyright:
# Copyright (C) 2009 SecPod, http://www.secpod.com
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2
# (or any later version), as published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
################################################################################
if(description)
{
display("secpad_ftp_anonymous being...\n");
script_oid("1.3.6.1.4.1.25623.1.0.108477");
script_version("2021-03-19T08:52:49+0000");
script_tag(name:"last_modification", value:"2021-03-19 08:52:49 +0000 (Fri, 19 Mar 2021)");
script_tag(name:"creation_date", value:"2009-03-12 10:50:11 +0100 (Thu, 12 Mar 2009)");
script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:N");
script_tag(name:"cvss_base", value:"0.0");
script_name("Anonymous FTP Login Detection");
script_category(ACT_GATHER_INFO);
script_copyright("Copyright (C) 2009 SecPod");
script_family("Service detection");
script_dependencies("find_service2.nasl", "find_service_3digits.nasl", "logins.nasl");
script_require_ports("Services/ftp", 21);
script_tag(name:"summary", value:"Checks if the remote FTP Server allows anonymous logins.
Note: The reporting takes place in a separate VT 'Anonymous FTP Login Reporting' (OID: 1.3.6.1.4.1.25623.1.0.900600).");
script_tag(name:"vuldetect", value:"Try to login with an anonymous account at the remote FTP Server.");
script_tag(name:"qod_type", value:"remote_banner");
exit(0);
}
include("misc_func.inc");
include("port_service_func.inc");
report = 'It was possible to login to the remote FTP service with the following anonymous account(s):\n\n';
listingReport = '\nHere are the contents of the remote FTP directory listing:\n';
#passwd = "anonymous@example.com";
passwd = "root";
display("secpad_ftp_anonymous....action...\n");
port = ftp_get_port( default:21 );
display("ftp_get_port is ", port,"\n");
foreach user( make_list( "anonymous", "ftp","root" ) ) {
soc1 = open_sock_tcp( port );
if( ! soc1 )
continue;
display("sco1:",soc1," user:",user," pass:",passwd,"\n");
login_details = ftp_log_in( socket:soc1, user:user, pass:passwd );
if( ! login_details ) {
ftp_close( socket:soc1 );
continue;
}
display("come in ftp,user:",user);
vuln = TRUE;
report += user + ':' + passwd + '\n';
set_kb_item( name:"ftp/" + port + "/anonymous", value:TRUE );
set_kb_item( name:"ftp/anonymous_ftp/detected", value:TRUE );
# TODO: We might want to check if ftp/login contains the "anonymous" user
# and ftp/password anonymous@example.com and then do a replace_kb_item()
# below to catch cases where only the ftp user is allowed to connect to
# the service.
if( ! get_kb_item( "ftp/login" ) ) {
set_kb_item( name:"ftp/login", value:user );
set_kb_item( name:"ftp/password", value:passwd );
}
if( ! get_kb_item( "ftp/anonymous/login" ) ) {
set_kb_item( name:"ftp/anonymous/login", value:user );
set_kb_item( name:"ftp/anonymous/password", value:passwd );
}
port2 = ftp_get_pasv_port( socket:soc1 );
if( ! port2 ) {
ftp_close( socket:soc1 );
continue;
}
soc2 = open_sock_tcp( port2, transport:get_port_transport( port ) );
if( ! soc2 ) {
ftp_close( socket:soc1 );
continue;
}
send( socket:soc1, data:'LIST /\r\n' );
listing = ftp_recv_listing( socket:soc2 );
close( soc2 );
ftp_close( socket:soc1 );
if( listing && strlen( listing ) ) {
listingAvailable = TRUE;
listingReport += '\nAccount "' + user + '":\n\n' + listing;
}
}
display("listingAvailable is ",listingAvailable);
if( vuln ) {
if( listingAvailable )
report += listingReport;
set_kb_item( name:"ftp/" + port + "/anonymous_report", value:report );
}
display(report);
exit( 0 );
执行命令
openvas-nasl -X -B -d -i ~/plug/plugins -t 172.16.83.228 ~/plug/plugins/find_service2.nasl ~/plug/plugins/find_service_3digits.nasl ~/plug/plugins/logins.nasl ~/plug/plugins/secpod_ftp_anonymous.nasl
-
这里注意下为什么要有find_service2.nasl、find_service_3digits.nasl、logins.nasl，因为在代码中有script_dependencies(“find_service2.nasl”, “find_service_3digits.nasl”, “logins.nasl”);，如果不带这openvas-nasl没法自动把依赖自动加进去，我们分别在find_service2.nasl、find_service_3digits.nasl、logins.nasl，添加了调试信息，一会就可以看到，
-
同时secpod_ftp_anonymous.nasl这个脚本中原始的带的用户名和密码，anonymous, ftp，anonymous@example.com，是没法执行进入目标机的，我在secpod_ftp_anonymous.nasl添加了目标机的用户名密码root下面是输出，
输出
root@wll:~# openvas-nasl -X -B -d -i ~/plug/plugins -t 172.16.83.228 ~/plug/plugins/find_service2.nasl ~/plug/plugins/find_service_3digits.nasl ~/plug/plugins/logins.nasl ~/plug/plugins/secpod_ftp_anonymous.nasl
lib nasl-Message: 07:11:19.820: find_service2.nasl..begin ...
lib nasl-Message: 07:11:19.914: begin find_service_3digits...
lib nasl-Message: 07:11:19.933: begin logins...
lib misc-Message: 07:11:19.939: set key ftp/writeable_dir -> /incoming
lib misc-Message: 07:11:19.941: set key ftp/login -> anonymous
lib misc-Message: 07:11:19.955: set key ftp/password -> anonymous@example.com
lib misc-Message: 07:11:19.955: set key SMB/dont_send_in_cleartext -> 1
lib misc-Message: 07:11:19.956: set key SMB/NTLMSSP -> 1
lib nasl-Message: 07:11:20.016: secpad_ftp_anonymous being...
lib nasl-Message: 07:11:20.039: secpad_ftp_anonymous....action...
lib nasl-Message: 07:11:20.040: begin ftp_get_port ..default is 21 nodefault is ignore_unscanned is
lib nasl-Message: 07:11:20.041: get_kb_item
lib nasl-Message: 07:11:20.041: ignore_unscanned is default is 1
lib nasl-Message: 07:11:20.049: get_port_state
lib nasl-Message: 07:11:20.054: end ftp_get_port ...
lib nasl-Message: 07:11:20.055: ftp_get_port is 21
lib nasl-Message: 07:11:20.065: sco1:1000000 user:anonymous pass:root
lib nasl-Message: 07:11:23.094: sco1:1000000 user:ftp pass:root
lib nasl-Message: 07:11:26.407: sco1:1000000 user:root pass:root
lib nasl-Message: 07:11:26.497: come in ftp,user:root
lib misc-Message: 07:11:26.515: set key ftp/21/anonymous -> 1
lib misc-Message: 07:11:26.517: set key ftp/anonymous_ftp/detected -> 1
lib misc-Message: 07:11:26.527: set key ftp/anonymous/login -> root
lib misc-Message: 07:11:26.533: set key ftp/anonymous/password -> root
lib nasl-Message: 07:11:26.593: listingAvailable is 1
lib misc-Message: 07:11:26.601: set key ftp/21/anonymous_report -> It was possible to login to the remote FTP service with the following anonymous account(s):
root:root
Here are the contents of the remote FTP directory listing:
Account "root":
-rw-r--r-- 1 0 0 9 Jan 05 11:41 3
-rw------- 1 0 0 738894 May 20 2020 ?\xba\xe2\xd7?\xbe.part3.rar
lib nasl-Message: 07:11:26.601: It was possible to login to the remote FTP service with the following anonymous account(s):
root:root
Here are the contents of the remote FTP directory listing:
Account "root":
-rw-r--r-- 1 0 0 9 Jan 05 11:41 3
-rw------- 1 0 0 738894 May 20 2020 .........part3.rar
ftp_get_pasv_port
在看代码的时候先打开open_sock_tcp，然后ftp_log_in 输入用户密码登录ftp_get_pasv_port 这个函数什么意思？
原来ftp发送数据有两种模式一种port、一种pasv
具体的https://blog.51cto.com/guailele/363557 可以看下
ftp clinet与server的通信过程
1、通过ssh的端口号，创建socket也就是代码里的port = ftp_get_port( default:21 );
2、通过这个port，来调用ftp ftp_log_in获取对应的用户名密码
3、port2 = ftp_get_pasv_port( socket:soc1 );获取传输数据server端的端口号
4、根据port2创建socket连接
5、从client 发送ftp 的命令LIST 查看ftp服务端的目录send( socket:soc1, data:’LIST /\r\n’ );
6、监听返回值listing = ftp_recv_listing( socket:soc2 );
7、close 端口
为了验证LIST就是返回的实际目录，通过工具WinSCP连接ftp服务，查看发下就是一个文件为3，一个中文名称+part3.rar