Bug 1260695 - php: Another use-after-free vulnerability in unserialize() with SplObjectStorage
Summary: php: Another use-after-free vulnerability in unserialize() with SplObjectStorage
Status: CLOSED DUPLICATE of bug 1260642
Alias: None
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard: impact=moderate,public=20150827,repor...
Keywords: Security
Depends On: 1260700
Blocks: 1260756
TreeView+ depends on / blocked
 
Reported: 2015-09-07 13:10 UTC by Adam Mariš
Modified: 2019-06-08 20:44 UTC (History)
15 users (show)

(edit)
Clone Of:
(edit)
Last Closed: 2015-09-09 08:27:02 UTC


Attachments (Terms of Use)

Description Adam Mariš 2015-09-07 13:10:07 UTC
Another user-after-free vulnerability was found in unserialize(). We can create ZVAL and free it. During deserialization it will still allow to use R: or r: to set references to already freed memory, which could possibly lead to remote code execution.

Vulnerable code:

ALLOC_INIT_ZVAL(pentry);
if (!php_var_unserialize(&pentry, &p, s + buf_len, &var_hash TSRMLS_CC)) {
	zval_ptr_dtor(&pentry);
	goto outexcept;
}
var_push_dtor(&var_hash, &pentry);
if(Z_TYPE_P(pentry) != IS_OBJECT) {
	goto outexcept;
}
ALLOC_INIT_ZVAL(pinf);
if (*p == ',') { /* new version has inf */
	++p;
	if (!php_var_unserialize(&pinf, &p, s + buf_len, &var_hash TSRMLS_CC)) {
		zval_ptr_dtor(&pinf);
		goto outexcept;
	}
}

Upstream report:

https://bugs.php.net/bug.php?id=70365

Upstream patch:

http://git.php.net/?p=php-src.git;a=commit;h=f06a069c462d37c2e009f6d1d93b8c8e7b713393

Comment 1 Adam Mariš 2015-09-07 13:17:49 UTC
Created php tracking bugs for this issue:

Affects: fedora-all [bug 1260700]

Comment 2 Adam Mariš 2015-09-09 08:27:02 UTC

*** This bug has been marked as a duplicate of bug 1260642 ***

Comment 3 Fedora Update System 2015-09-14 22:19:58 UTC
php-5.6.13-1.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.

Comment 4 Fedora Update System 2015-09-14 23:18:53 UTC
php-5.6.13-1.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.

Comment 5 Fedora Update System 2015-09-18 18:43:56 UTC
php-5.6.13-1.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.


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