Bug 741020 (CVE-2011-3379) - CVE-2011-3379 php: changes to is_a() in 5.3.7 may allow arbitrary code execution with certain code
Summary: CVE-2011-3379 php: changes to is_a() in 5.3.7 may allow arbitrary code execut...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2011-3379
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=20110923,repor...
Depends On: 741022
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-09-24 13:45 UTC by Vincent Danen
Modified: 2019-06-08 18:55 UTC (History)
3 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2012-06-05 09:41:26 UTC


Attachments (Terms of Use)

Description Vincent Danen 2011-09-24 13:45:57 UTC
It was reported [1],[2] that due to changes in the is_a() function [3],[4] PHP 5.3.7 and 5.3.8 became vulnerable to remote arbitrary code execution when is_a() is used in certain ways.  Due to the __autoload() implementation, if a user were able to upload a crafted file, it could be possible to pass the contents of the file as an argument to the __autoload() function which could in turn use that argument as a file to include().  If there was no adequate checking or enforcement of the file to load being, local, this could lead to including a remote script from a remote web site.

An example of a vulnerable __autoload() function could be:

function __autoload($class_name) {
    include $class_name . '.php';
}

In the above example, were $class_name to include a remote URL, and if allow_url_fopen was enabled in php.ini, this could result in loading a remote PHP script on the server.

This flaw does not affect PHP versions prior to 5.3.7 were this change was introduced.  A fix is in PHP's subversion repository (r317183) [5].

[1] http://www.byte.nl/blog/2011/09/23/security-bug-in-is_a-function-in-php-5-3-7-5-3-8/
[2] https://bugs.php.net/bug.php?id=55475
[3] https://bugs.php.net/bug.php?id=53727
[4] http://svn.php.net/viewvc/?view=revision&revision=312904
[5] http://svn.php.net/viewvc/?view=revision&revision=317183


Statement:

Not vulnerable. This issue did not affect the versions of php as shipped with Red Hat Enterprise Linux 4, 5, or 6.

Comment 1 Vincent Danen 2011-09-24 13:52:09 UTC
Created php tracking bugs for this issue

Affects: fedora-all [bug 741022]

Comment 2 Vincent Danen 2011-09-26 15:21:28 UTC
A better (and less restrictive) work-around for this flaw is to disable allow_url_include rather than allow_url_fopen.

Comment 3 Vincent Danen 2011-09-28 00:06:31 UTC
This has been assigned the name CVE-2011-3379

Comment 4 Fedora Update System 2011-10-08 17:58:44 UTC
php-5.3.8-3.fc15 has been pushed to the Fedora 15 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 5 Fedora Update System 2011-10-08 18:03:09 UTC
php-5.3.8-3.fc14 has been pushed to the Fedora 14 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 6 Fedora Update System 2011-10-09 19:33:58 UTC
php-5.3.8-3.fc16 has been pushed to the Fedora 16 stable repository.  If problems still persist, please make note of it in this bug report.


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