#45301 [Com]: Serious flaw in random related functions and possibly file or memory corruption
| From: | sv4php at fmethod dot com | Date: | Wed, 18 Jun 2008 18:06:09 +0000 |
| Subject: | #45301 [Com]: Serious flaw in random related functions and possibly file or memory corruption | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-125854@lists.php.net to get a copy of this message | ||
ID: 45301
Comment by: sv4php at fmethod dot com
Reported By: payton2558 at googlemail dot com
Status: Open
Bug Type: Unknown/Other Function
Operating System: Windows XP 32, Vista 32
PHP Version: 5.2.6
New Comment:
Confirmed on Apache 2.2, Windows XP SP2 with PHP 5.2.6.
Confirmed also without building files (just building the array directly
in a loop).
Requires Windows, doesn't seem to affect mt_rand();
Previous Comments:
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[2008-06-18 16:20:47] pajoye@php.net
On a related note: #45184
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[2008-06-18 16:05:00] payton2558 at googlemail dot com
Description:
------------
The reproduce code demonstrates the bug. You can modify the code in
different ways to affect the severity of the output.
Appears to require Windows.
Please note I have tested on 2 different machines and 3 versions of
php. I have also confirmed this with a couple of users on IRC.
mt_rand may also be affected but not as badly
Unrelated: bugs.php your CAPTCHA system is the worst I could ever
expect for a programming related group
Reproduce code:
---------------
<?php
function RandomNumber() {
$word1 = file('word1.txt'); // word1 and word2.txt can be made by
fwriting "word\n" 50000 times. Different filesizes affect bug.
$word2 = file('word2.txt');
$rword1 = trim($word1[array_rand($word1)]);
$rword2 = trim($word2[array_rand($word2)]);
$rnum = rand(1,999);
return $rnum;
}
for ($i=0; $i<20; $i++) {
echo RandomNumber()."\n";
}
?>
Expected result:
----------------
20 random looking numbers
Actual result:
--------------
20 identical numbers or in other cases, severely unrandom numbers
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Edit this bug report at http://bugs.php.net/?id=45301&edit=1